Fuego

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  • 14.473°N
  • 90.88°W

  • 3763 m
    12343 ft

  • 342090
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Most Recent Weekly Report: 10 September-16 September 2014


During 10-16 September INSIVUMEH reported that white fumarolic plumes rose 200-600 m above Fuego’s summit. Variable explosions generated ash plumes 500-1,00 m above the summit; during 24-hour periods there were daily counts of 28, 32, 21, 12, 0, 8, and 11. The lava flow was active within the Ceniza drainage (SSW) on 13 September and had extended 100 m.

Moderate rumbling was heard and shockwaves caused roofs to shake on some houses near the volcano. On 10-13, 15, and 16 September incandescent plumes were observed 100-200 m above the crater.

Weak avalanches were frequently channeled into the drainages of Ceniza, Trinidad (S), Taniluyá (SW), Santa Teresa (W), Las Lajas (SE), and Honda (E) during 10-16 September.

During 10-13 and 15 September fine gray ash from explosions fell over the areas of Sangre de Cristo (8 km WSW), Panimaché I and II (8 km SW), Morelia (10 km SW), Santa Sofía (12 km SW), and others. During 14 September ashfall was reported in Yepocapa (8 km WNW), Panimaché, Sangre de Cristo, Morelia, and others. During 16 September ashfall was reported in Alotenango (8 km ENE), Antigua (18 km NE), Ciudad Vieja (13.5 km NE), and other areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


Most Recent Bulletin Report: April 2014 (BGVN 39:04)


Explosions, ash plumes, lava flows, and lahars during April 2013-June 2014

In this report we highlight Fuego's ongoing eruptive activity during April 2013-June 2014. During this reporting period continued monitoring by the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) included ground-based observations, field visits, and seismic monitoring. Aviation reports were abundant from the Washington Volcanic Ash Advisory Center (VAAC). The active summit crater was a frequent source of thermal alerts from the MODVOLC system which is based on infrared radiation detected in space by the MODIS instruments.

Advancing lava flows and ash explosions. INSIVUMEH reported that lava flows advanced from Fuego's summit during the entire reporting interval. By 29 June 2014, a lava flow was extending 150 m toward the TaniluyÁ drainage and generating avalanches that reached the Ceniza drainage. Earlier in the year, lava flows up to 550 m long reached vegetated areas on the SW flank.

INSIVUMEH and Washington VAAC reported frequent ash explosions from Fuego's summit crater during April 2013-June 2014 (figure 28). Ash plumes typically rose 100-800 m above the summit. Significant ash plumes drifted 10-20 km from the summit in the direction of prevailing winds. An exceptional case occurred when ash drifted 30 km NW during activity on 30 December 2013. Constant fumarolic activity generated diffuse, white plumes that rose approximately 150 m above the summit. Incandescent explosions were also frequently observed at night and reached 200 m above the summit (figure 29).

Figure 28. Two satellite images captured incandescence from Fuego on 18 January 2014 (top) and 4 December 2013 (bottom). (top) This EO-1 ALI image is the product of 3 bands: band 10 for thermal, band 9 for clouds, and band 4 for near-infrared. A small, round ash plume was also visible drifting NE of the summit. (bottom) This Landsat 8 image is a combination of visible and infrared bands (band 7 for near-infrared, band 6 for thermal infrared, and band 3 for chlorophyll absorption). Image processed by Rüdiger Escobar Wolf (Michigan Tech University) and acquired by NASA/USGS.
Figure 29. Comparisons of infrared video images with seismic traces for Fuego during 21-22 April 2014. These still views (A-C) enabled viewers to gauge the degree, timing, and correlation between major explosions accompanied by incandescence and seismic signals. The respective images coincide with the points along the seismic trace intersected with the heavy black vertical lines. Courtesy of Rüdiger Escobar Wolf (https://www.youtube.com/watch?v=mvGw7AUCtCo), INSIVUMEH, US-AID, and Michigan Tech University.

Figure 29 shows moderate-sized (~200-m-high) incandescent plumes occurring at the time of high-amplitude seismic signals (panels A and B) whereas minor explosions (panel C) produced little-to-no seismic signal (note that no significant seismicity occurred near the 10:20 tickmark). The Michigan Tech research team postulated that the lack of seismic signal in panel C is the result of the seismometer only registering the ground coupled airwaves during the sequence as opposed to the explosion signature (personal communication by Rüdiger Escobar-Wolf). Some of the explosions recorded during this time were heard in neighboring communities.

Shockwaves from explosions, rumbling from avalanches, and ashfall from explosive events were frequently reported by inhabitants from local communities (table 9). Windows and metal roofs rattled during major events and there were such numerous reports received by INSIVUMEH from residents within 10 km of the summit.

Table 9. Ashfall from explosions at Fuego was reported in numerous communities during 27 March 2013 - 19 June 2014. A map of town locations can be found in BGVN 36:06, figure 16. Courtesy of INSIVUMEH.

Year Date Town reporting ashfall
2013 27 March-2 April Panimaché I and II (8 km SW), Morelia (9 km SW), and Hagia Sophía
28 Jun. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
18 Nov. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
21 Nov. Sangre de Cristo (8 km WSW)
2014 3 Jan. Panimaché (8 km SW), Morelia (9 km SW), and Sofía I and II (12 km SW)
13 Jan. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
2 Feb. Panimaché (8 km SW), Morelia (9 km SW), and the W flank
25 Mar. Sangre de Cristo (8 km WSW) and surrounding areas
22-23 Mar. Santa Sofía (12 km SW), Panimaché I and II (8 km SW), Morelia (9 km SW)
10-11 Apr. Panimaché (8 km SW) and Sangre de Cristo (8 km WSW)
20-22 Apr. Panimaché (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW)
25-28 Apr. Panimaché (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW)
18-19 Jun. Within 15 km of the summit, mainly El Porvenir (8 km ENE), Los Yucales (12 km SW), Santa Sofía (12 km SW), Morelia (10 km SW), and Panimaché (I and II, ~8 km SW). Also, ashfall was reported in Sangre de Cristo (8 km WSW) on 18 June.

Thermal anomaly detection during 2013-2014. Except for June 2014, hotspots at the summit region were detected by satellite remote sensing instruments during each month of this reporting period (table 10). Platforms capturing the infrared data included MODIS (onboard the Terra and Aqua satellites), Landsat 8, and EO-1 Advanced Land Imaging (ALI).

Table 10. The MODVOLC system generated thermal alerts from Fuego during April 2013-May 2014. Courtesy of HIGP.

Year Month Day #Pixels/Day
2013 Apr. 14 2
Apr. 21 1
Apr. 23 1
Apr. 25 2
Apr. 26 3
Apr. 27 4
Apr. 28 9
May 9 1
Jun. 15 1
Jun. 17 1
Jul. 8 2
Jul. 10 2
Jul. 12 1
Jul. 15 1
Jul. 22 2
Jul. 26 1
Jul. 28 2
Jul. 29 1
Aug. 8 1
Aug. 9 1
Aug. 11 1
Aug. 15 2
Aug. 18 2
Aug. 19 1
Aug. 20 4
Aug. 23 1
Sept. 3 1
Sept. 14 1
Oct. 5 1
Oct. 11 2
Oct. 14 2
Nov. 4 4
Nov. 15 1
Nov. 18 1
Nov. 19 3
Nov. 20 2
Nov. 24 2
Nov. 27 1
Dec. 3 1
Dec. 5 1
Dec. 10 2
Dec. 15 5
Dec. 16 2
Dec. 28 2
Dec. 30 1
2014 Jan. 2 1
Jan. 5 1
Jan. 7 4
Jan. 11 1
Jan. 15 2
Jan. 18 5
Jan. 20 1
Jan. 22 1
Jan. 23 2
Jan. 25 5
Jan. 28 1
Jan. 29 2
Jan. 31 1
Feb. 2 1
Feb. 4 1
Feb. 5 5
Feb. 6 1
Feb. 7 1
Feb. 8 1
Feb. 12 1
Feb. 21 2
Feb. 24 1
Mar. 1 1
Mar. 5 1
Mar. 11 3
Mar. 20 1
Mar. 21 1
Mar. 23 4
Mar. 25 2
Mar. 27 1
Mar. 28 1
Mar. 29 1
Mar. 30 2
Apr. 1 1
Apr. 15 1
Apr. 16 1
Apr. 21 1
Apr. 22 1
Apr. 27 1
May 17 1
May 18 2
May 19 2

Lahar hazards. Drainages within the southern sector of Fuego were frequently at risk for lahars during 2013-2014. In particular, the rivers Las Lajas, El Jute, Honda, Seca, Ceniza, Santa Teresa, and TaniluyÁ were inundated by lahars during this reporting period (table 11). A map of river locations can be found in figure 7 of BGVN 30:08.

Table 11. During May 2013- June 2014, weak- to strong-flowing lahars from Fuego were frequently triggered by heavy rainfall, mainly during May-September (the rainy season) each year. Courtesy of INSIVUMEH.

Year Date Drainages Dimensions Load Damage/At risk
2014 9 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks na
5 Jun. Honda (E), El Jute (SE), Ceniza (SSW), & Santa Teresa (S) na 1.5 m diameter blocks na
2 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks na
1 Jun. Las Lajas (SE), Honda (E), & Seca (W) na na Traffic crossing the Río Seca was disrupted as well as the road crossing on the W and S sides
2013 11 Sept. Las Lajas & El Jute (SE) 30 m wide; 4 m deep 2 m diameter blocks; branches and tree trunks na
10 Sept. Taniluyá (SW) 15-20 m wide; 1-2 m deep Tree trunks Roads were blocked in Panimaché I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW) for two hours
9 Sept. Las Lajas & El Jute (SE) na 2 m diameter blocks na
17 Aug. Las Lajas, Ceniza (SSW), & El Jute (SE) 30 m wide blocks na
5 Jul. Las Lajas & El Jute (SE) na 0.5 m in diameter na
27 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks; branches and tree trunks na
8 Jun. Las Lajas (SE), El Jute (SE), &Ceniza (SSW) na na na
2 Jun. Ceniza (SSW) blocks; trees and logs na na
29 May Las Lajas & El Jute (SE) na 0.5 m in diameter na

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/inicio.html); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (URL: http://conred.gob.gt/www/); and Washington Volcanic Ash Advisory Center (VAAC), NOAA Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC).

Index of Weekly Reports


2014: January | February | March | April | May | June | July | August | September
2013: January | February | March | April | May | June | July | August | September | October | November | December
2012: January | February | March | April | May | June | July | August | September | October | November | December
2011: January | February | March | April | June | July | September | October | November | December
2010: January | February | April | May | June | July | August | September | October | November | December
2009: January | February | March | April | May | June | July | August | September | October | November | December
2008: January | February | March | April | May | June | July | August | September | November | December
2007: January | March | April | May | June | July | August | October | November | December
2006: January | February | March | April | May | June | August | September | November
2005: January | March | April | May | June | July | September | November | December
2004: January | February | March | April | May | June | July | August | September | October | November | December
2003: January | April | June | July | September | October | November | December
2002: January | February | August | December
2000: December

Weekly Reports


10 September-16 September 2014

During 10-16 September INSIVUMEH reported that white fumarolic plumes rose 200-600 m above Fuego’s summit. Variable explosions generated ash plumes 500-1,00 m above the summit; during 24-hour periods there were daily counts of 28, 32, 21, 12, 0, 8, and 11. The lava flow was active within the Ceniza drainage (SSW) on 13 September and had extended 100 m.

Moderate rumbling was heard and shockwaves caused roofs to shake on some houses near the volcano. On 10-13, 15, and 16 September incandescent plumes were observed 100-200 m above the crater.

Weak avalanches were frequently channeled into the drainages of Ceniza, Trinidad (S), Taniluyá (SW), Santa Teresa (W), Las Lajas (SE), and Honda (E) during 10-16 September.

During 10-13 and 15 September fine gray ash from explosions fell over the areas of Sangre de Cristo (8 km WSW), Panimaché I and II (8 km SW), Morelia (10 km SW), Santa Sofía (12 km SW), and others. During 14 September ashfall was reported in Yepocapa (8 km WNW), Panimaché, Sangre de Cristo, Morelia, and others. During 16 September ashfall was reported in Alotenango (8 km ENE), Antigua (18 km NE), Ciudad Vieja (13.5 km NE), and other areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 September-9 September 2014

On 2 September INSIVUMEH seismically detected a lahar flowing through Fuego’s Taniluyá drainage (SW flank). Observations determined a width of 75 m and height of 2.5 m. The flow cut the road between Santa Lucia Cotzulmaguapa and the communities of Morelia, Santa Sofía, and Panimaché I and II. Lahars were also detected within Río Ceniza (SSW) and Santa Teresa (W).

During 3-9 September INSIVUMEH reported that white fumarolic plumes rose 300-600 m above Fuego’s summit. Weak-to-moderate ash explosions occurred each day and generated plumes 500-800 m high; ash plumes drifted up to 15 km away with prevailing winds. Moderate rumbling was heard and shockwaves caused roofs to shake on some houses near the volcano. On 3 and 5-9 September incandescent plumes were observed 75-150 m above the crater. Weak avalanches were channeled into the drainages of Ceniza (SSW), Trinidad (S), Taniluyá (SW), Santa Teresa, Las Lajas, and Honda during 9 September.

During 3-4 and 6-9 September fine gray ash from explosions fell over the areas of Yepocapa (8 km WNW), Sangre de Cristo (8 km WSW), Panimaché I and II (8 km SW), Morelia (10 km SW), Santa Sofía (12 km SW), Yucales (12 km SW), Porvenir (8 km ENE), and others.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 August-2 September 2014

During 27 August-2 September, INSIVUMEH reported that weak to moderate explosions at Fuego expelled blocks up to 800 m above the rim. On most days white plumes rose 200-600 m above the crater; on 28 August it rose to 4.3 km (14,100 ft) above the crater. Ash plumes rose 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted 10-15 km NE, E, SE, W, S, and SW. Ashfall was reported in the villages of Morelia (9 km SW), Panimaché (8 km SW), Panimaché II, Sangre de Cristo (8 km WSW), Hagia Sophia, Santa Sofia, Yepocapa, Alotenango, Antigua, and San Miguel Dueñas. On most days rumbling was heard that rattled structures near the volcano. On 30-31 August lava flowed towards Ceniza Canyon. Weak to moderate avalanches of blocks were channeled into the canyons Las Lajas (SE), Ceniza (SSW), Taniluyá (SW), Santa Teresa, and Honda.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 August-26 August 2014

During 20-26 August, INSIVUMEH reported that weak to moderate explosions at Fuego expelled blocks up to 800 m above the rim. On most days white plumes rose 200-600 m above the crater and drifted SW and W and on 25 August the white plume rose to 4.2 km (13,800 ft) above the crater. Ash plumes rose 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted 10-15 km NE, W, S and SW. Ashfall was reported in villages Morelia (9 km SW), Panimaché (8 km SW), Panimaché II, Sangre de Cristo (8 km WSW), and Hagia Sophia. On most days rumbling was heard around the volcano and rattled structures near the volcano on 24 August. On 21 and 25 August were jet engine like sounds lasting 1-4 minutes. Weak to moderate avalanches of blocks were channeled into the canyons Las Lajas (SE), Trinidad (S), Ceniza (SSW), Taniluyá (SW), Santa Teresa and Honda.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 August-19 August 2014

During 13-19 August, INSIVUMEH reported weak to moderate explosions at Fuego with incandescent blocks being expelled 500-800 m above the crater, activity accompanied on 14 and 16 August by white plumes that rose 200-300 m above the crater and drifted W. On 13 and 15 August INSIVUMEH reported rumbling from shock waves that rattled structures up to 8 km from the volcano in the villages of Panimaché I and II, Morelia, and others in this area, and on 17 August jet engine like sounds lasting 1-4 minutes. On most days incandescent blocks were expelled 50-400 m above the crater, and weak to moderate avalanches of blocks were channeled into the Las Lajas (SE), Trinidad (S), Ceniza (SSW), Taniluyá (SW), Santa Teresa and Barranca Honda canyons. Ash plumes rose 4.2-4.5 km (13,800-14,800 ft) a.s.l. and drifted 8-15 km W and SW. Ashfall was reported in Morelia (9 km SW), Panimaché (8 km SW), Panimaché II, Sangre de Cristo (8 km WSW), Yepocapa (8 km WNW), and Hagia Sophia. On 18 August the Washington VAAC reported several discrete ash emissions based on satellite and wind data.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


6 August-12 August 2014

During 6-12 August, INSIVUMEH reported weak to moderate explosions at Fuego with incandescent blocks being expelled 500-800 m above the crater accompanied by ash that rose 300-400 m above the crater and drifted W and produced rumbling from shock waves that rattled structures up to 8 km from the volcano. On most days, incandescent blocks were expelled 100-200 m above the crater and weak to moderate avalanches of blocks were channeled into the canyons Las Lajas (SE), Trinidad (S), Ceniza (SSW), Taniluyá (SW) and Barranca Honda. Dark gray to white plumes rose 4.0-4.6 km (13,100-15,100 ft) a.s.l. and drifted 8-15 km W and SW. Ashfall was reported in villages of Morelia (9 km SW), Panimaché (8 km SW), Panimaché II, Sangre de Cristo (8 km WSW), Yepocapa (8 km WNW), Hagia Sophia, and around the Observatory. On 6-8 August Washington VAAC reported ongoing emissions and on 7 August an ash plume rose to 4.5 km (15000 ft) a.s.l.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


30 July-5 August 2014

During 30 July-5 August, INSIVUMEH reported weak to moderate explosions at Fuego with incandescent blocks expelled 100-200 m above the crater accompanied by minor gray ash 300-400 m above the crater that drifted S. Shock waves from those explosions produced rumbling that rattled structures up to 4 km from the volcano. On most days, weak to moderate avalanches of blocks moved down the flanks towards Taniluya, Ceniza and Santa Teresa canyons. Gray to white plumes rose 4.2-4.6 km (13,800-15,100 ft) a.s.l. and drifted 9-12 km W and SW. Ashfall was reported in villages of Yepocapa, Finca La Conchita, Sangre de Cristo, Morelia and Panimaché.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 July-29 July 2014

During 23-29 July INSIVUMEH reported moderate to strong explosions at Fuego, with incandescent blocks being expelled 100-200 m above the crater accompanied by moderate to dark gray ash 400-600 m above the crater that drifted NW, W, and SW. On most days avalanches moved down the flanks. Columns, described as containing ash on 24 and 28 July, rose 4-4.6 km (13,100-15,100 ft) a.s.l. and drifted 8-12 km NE, NW, W, and SW. A weak white fumarolic plume rose above Fuego’s summit crater on 27-28 July. During 26-27 July, rumbling was heard up to 15 km away. Ashfall was reported most days in nearby areas, including the Santa Teresa, Taniluya, Ceniza, and Trinidad drainages, and at the Observatory, Morelia, Hagia Sophia, Ingenio los Tarros, Panimaché, Santa Sofia, Yepocapa, and Finca La Conchita.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 July-22 July 2014

During 16-22 July, INSIVUMEH reported moderate to strong explosions at Fuego with incandescent blocks being expelled 200-500 m above the crater. On July 22 the explosions also ejected gray ash. Most days weak avalanches moved down the flanks. Light gray eruption columns reported on 16 July rose 4-4.5 km (13,100-14,800 ft) a.s.l. and drifted 7-10 km W, SW, WSW, E, and NE. Weak white fumarolic plume rose 200-300 m above Fuego’s summit crater. A special bulletin on 18 July noted an increased number of explosions and a change in the eruptive pattern. Rumbling and jetting sounds often accompanied moderate to strong explosions that produced shock waves 12-15 km away and rattled structures in Panimache and Morelia on the flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 July-15 July 2014

During 30 June-14 July, INSIVUMEH frequently reported a white fumarolic plume rising from Fuego’s summit extending up to 4,000 m (13,123 ft) a.s.l.. Weak-to-moderate explosions generated ash plumes to similar heights during 30 June and 1, 4, 6, 7, and 9-13 July. Rumbling and jetting sounds often accompanied these explosions, often with durations of 1-5 minutes. Pulses of incandescence reached 50-100 m above the rim on 30 June, and 6, 7, and 12 July. Remobilized ash reduced visibility on 4, 9, and 10 July. Surges of lava and incandescent avalanches traveled from the summit down the flanks on 1 July (~150 m into the Trinidad drainage), 6 July (100 m into Taniluya and 200 m into the Ceniza), 11 July (~100 m into Taniluya), 12 July (Santa Teresa, Taniluya, Ceniza, Trinidad, Las Lajas, and Honda), and 13 July (~400 m into the Ceniza).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 June-1 July 2014

INSIVUMEH reported that on 25-29 June weak to moderate explosions generated ash plumes that rose 500-800 m above the crater and drifted 10-12 km W, NW, and SE. Incandescent material that was ejected 100-200 m above the crater landed on the flank and formed avalanches. A lava flow from the crater moving SW towards the Tanilaya drainage generated avalanches into the Ceniza drainage (SSW). On 26 June explosions generated moderate and strong acoustic waves that sounded like a quiet jet engine for a period of 1-2 minutes.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 June-24 June 2014

INSIVUMEH reported that, during 18-24 June, 7-23 explosions occurred per day at Fuego, generating weak-to-moderate ash plumes to 3,900-4,400 m (12,800-14,400 ft) a.s.l. and drifting with prevailing winds. The explosions during 17-18, 22, and 24 June were accompanied by rumbling sounds, some resembling jet engines that persisted for 1-5 minutes. Small avalanches occurred within the crater and local drainages due to explosion shockwaves on 19 June.

Fine ashfall from explosions on 18-19 June was reported in towns within 15 km of the summit, mainly El Porvenir (8 km ENE), Los Yucales (12 km SW), Santa Sofía (12 km SW), Morelia (10 km SW), and Panimaché (I and II, ~8 km SW). Additionally, ashfall was reported in Sangre de Cristo on 18 June. During 20, 22, and 24 June, incandescence from the summit reached 100-150 m above the crater rim and formed weak avalanches in the immediate summit area. Fumarolic activity continued during 18-24 June, generating white plumes rising to less than 4,200 m (13,800 ft) a.s.l.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 June-17 June 2014

INSIVUMEH reported that explosive activity from Fuego continued in mid-June. Explosions during 12-14 June sent ash plumes as high as 4,600 m (15,000 ft) a.s.l. that drifted 9-11 km S and W. Small avalanches also continued.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


4 June-10 June 2014

INSIVUMEH reported that on 5 June lahars descended Fuego's Honda (E), El Jute (SE), Ceniza (SSW), and Santa Teresa (S) drainages, carrying blocks as large as 1.5 m in diameter. Explosions during 5-6 June generated ash plumes that rose 250-350 m and drifted 8-10 km W and NW. Explosions during 8-10 June generated ash plumes that rose 350-750 m and drifted 8-10 km N. Incandescent material ejected 100 m above the crater landed on the flank and formed avalanches. On 9 June lahars in the El Jute and Las Lajas drainages carried blocks up to 1.5 m in diameter.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 May-3 June 2014

INSIVUMEH reported that during 31 May-1 June explosions at Fuego produced ash plumes that rose 350-550 m above the crater and drifted 8 km WNW. During the afternoon and evening of 1 June lahars descended the Las Lajas (SE) and Honda (E) drainages, as well as the Seca (W) drainage which disrupted traffic. Other sections of roadway to the W and S were also affected. Heavy rain continued on 2 June; lahars descended the Las Lajas and El Jute (SE) drainages, carrying blocks as large as 1.5 m in diameter. Explosions during 2-3 June generated ash plumes that rose 550-650 m and drifted 8 km S and SW. Incandescence rose above the crater and avalanches descended the Taniluyá (SW), Trinidad (S), and Ceniza (SSW) drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 April-29 April 2014

INSIVUMEH noted in a special report from 25 April that explosions at Fuego were occurring at a rate of 5-6 per hour, generating ash plumes that rose 350-650 m above the crater and drifting 10 km S and SW. Ashfall was reported in Panimaché, Morelia, and Santa Sofía; shock waves vibrated houses in those three towns among others. Avalanches of incandescent blocks reached vegetated areas. Explosions during 26-28 April produced ash plumes that rose 350-800 m and drifted 10 km W. Villagers in Panimaché, Morelia, and Santa Sofía again reported vibrating houses and ashfall. Block avalanches originated from the crater and descended the flanks. During 28-29 April explosions were detected at a rate of 6-8 per hour. Ash plumes rose 750 m and drifted 10 km W and NW. Explosions caused houses on the SW flank to vibrate.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 April-22 April 2014

INSIVUMEH noted in special reports that during 20-22 April explosions from Fuego generated ash plumes that rose 750 m above the crater and drifted 10-12 km NW, W, SW, and S. Ashfall was reported in villages downwind, including Panimaché (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW). Explosions were audible up to 30 km away, and shock waves detected more than 15 km away vibrated houses in Panimaché, Morelia, Santa Sofía, and other areas. Avalanches of blocks reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 April-15 April 2014

INSIVUMEH reported that during 9-10 April seismic activity at Fuego increased, along with the number and magnitude of explosions. Ash plumes rose 850 m above the crater and drifted 10 km W and SW. Explosions were heard in areas up to 15 km away and shock waves were detected 8 km away. At night incandescent blocks in the Santa Teresa (S), Ceniza (SSW), and Trinidad (S) drainages were noted. During 10-11 April explosions produced ash plumes that rose 500-800 m and drifted 8-10 km W and SW, and caused structures to vibrate in local towns. In a special report from 11 April INSIVUMEH noted that activity had increased. Ash plumes rose as high as 1.1 km and drifted 12 km W. Ashfall was reported in areas downwind, including Panimaché (8 km SW) and Sangre de Cristo (8 km WSW). Avalanches descended the Trinity drainage. Activity continued during 13-14 April though cloud cover prevented visual observations; explosions generated shock waves, and sounds resembling avalanches on the S and SW flanks were reported. During 14-15 April explosions produced ash plumes that rose 760 m and drifted 10 km W and SW. Shock waves were detected in areas within 10 km and explosions were heard within 15 km. At night incandescent blocks in the Santa Teresa (S), Ceniza (SSW), and Trinidad (S) drainages were again noted.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 March-25 March 2014

INSIVUMEH reported that during 20-21 March explosions at Fuego produced ash plumes that rose 500-800 m above the crater and drifted 9-10 km W. Incandescent material was ejected 200 m high. Later on 21 March seismicity increased. The number of explosions also increased to 7-9 moderate to strong explosions per hour. Ash plumes rose 750-950 m and drifted 15 km WSW. Shock waves vibrated structures in areas 8 km away, including Santa Sofía (12 km SW), Panimaché (8 km SW), and Morelia (9 km SW). During 22-23 March explosions generated ash plumes that rose 500-800 m and drifted 10-12 km S and SW. Incandescent material was ejected 200 m high. Ashfall was reported in Santa Sofía, Panimaché, Panimaché II (8 km SW), and Morelia. On 25 March INSIVUMEH noted that activity remained high; 8-14 explosions per hour generated ash plumes that rose 850-1,050 m and drifted 12 km W and SW. Ashfall was reported in Sangre de Cristo (8 km WSW) and surrounding areas. Explosions again vibrated structures in Santa Sofía, Panimaché, Panimaché II, and Morelia.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


12 February-18 February 2014

INSIVUMEH reported that during 13-14 February explosions at Fuego produced ash plumes that rose 500-1,000 m above the crater and drifted 8-10 km N and NE. Incandescent material was ejected 200 m high, and avalanches descended the Ceniza (SSW), Trinidad, Las Lajas (SE), and Honda drainages. On 16 February explosions produced ash plumes that rose 500-700 m above the crater and drifted 10 km SW, S, and SE. Shock waves were detected 20-25 km away in Escuintla (20 km SSE), Santa Lucia Cotzulmaguapa (20 km SW), Yepocapa (8 km WNW), Alotengando (8 km W), and Antigua Guatemala (18 km NE). Explosions continued during 16-17 February; ash plumes rose 300-1,100 m above the crater and drifted 15-17 km. Incandescent material was ejected 100-200 m high, and avalanches descended the Taniluyá (SW), Ceniza, Trinidad, and Santa Teresa (S) drainages, reaching vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 January-21 January 2014

INSIVUMEH reported that during 16-18 January explosions at Fuego produced ash plumes that rose 450-550 m above the crater. A lava flow in the Trinidad (S) drainage was 400 m long and generated avalanches. Other avalanches from the crater descended the Taniluya (SW), Ceniza (SSW), Trinidad, Las Lajas (SE), and Honda (E) drainages. Explosions during 19-20 January produced ash plumes that rose 500-800 m and drifted 10 km SE. Incandescent material was ejected 100-150 high and avalanches continued to descend multiple drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 January-14 January 2014

In a special report, INSIVUMEH reported that on 7 January seismicity at Fuego increased. Explosions generated shock waves that vibrated structures more than 15 km away, and rumbling noises were audible 30 km away. Ash plumes rose 4.2 km above the crater and drifted 10 km SW. Lava flowed 500 m down the SW flank and produced avalanches that reached vegetated areas. During 9-10 January Vulcanian explosions generated shock waves detected within 10 km, ejected pulses of incandescent material 100 m high, and produced ash plumes that rose 300 m and drifted 10 km NE. Avalanches descended the Ceniza (SSW), Trinidad (S), and Taniluya (SW) drainages, and lava flows continued to descend the flanks. During 10-11 January explosions produced shock waves, and ash plumes that rose 650 m and drifted S, SW, and W. Crater incandescence was observed at night. During 12-13 January explosions caused shock waves that vibrated structures in Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Ceilán, La Rochela, and San Andrés Osuna. Ash plumes rose 350-650 m and drifted 10 km SW and W. Incandescent material was ejected 200 m above the crater and avalanches descended the Taniluya, Ceniza, Trinidad, Las Lajas (SE), and Honda (E) drainages. A 200-m-long lava flow traveled down the Trinidad drainage. Seismicity remained high on 13 January. Ashfall was reported in Panimaché, Morelia, and Sangre de Cristo (8 km WSW). A 500-m-long lava flow remained active in the Ceniza drainage. On 14 January explosions generated shock waves audible 8 km away, ejected incandescent material 150 m high, and produced ash plumes that rose 300-800 m and drifted 8 km W and SW. Avalanches again descended multiple flanks. Ash fell in Santa Sofía, Panimaché, Morelia, and Sangre de Cristo.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 January-7 January 2014

Based on analyses of satellite images, the Washington VAAC reported that on 30 December 2013 an ash plume from Fuego drifted almost 30 km NW. INSIVUMEH reported that during 2-3 and 5-7 January 2014 explosions generated shock waves, ejected incandescent material as high as 250 m, and produced ash plumes that rose 300-700 m and drifted 7-12 km W and SW. Ashfall was reported in Panimache (8 km SW), Morelia (9 km SW), and Sofía I and II (12 km SW). Avalanches descended the Ceniza (SSW), Trinidad (S), Taniluya (SW), Las Lajas (SE), and Honda drainages.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


11 December-17 December 2013

In a special report INSIVUMEH noted that activity at Fuego had increased on 15 December. Lava flows were 500 m long in the Ceniza drainage (SSW), and their emission rate rate had increased. Blocks from lava-flow fronts reached vegetated areas. Six to eight explosions per hour produced ash plumes that rose 550 m and drifted 8 km. The explosions generated shock waves and rattled buildings in nearby villages. The next day lava flows were 600 m long in the Ceniza drainage. Explosions generated ash plumes that rose 450 m and drifted W and SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 November-26 November 2013

On 21 November INSIVUMEH reported that a recent Strombolian phase at Fuego decreased in intensity. Explosions generated ash plumes that rose 450 m and drifted W and SW. Ashfall was reported in Sangre de Cristo (8 km WSW). During 21-22 November explosions produced ash plumes that rose 450 m and drifted 7 km WNW, as well as loud rumbling sounds heard within 15 km. Lava flows were 300 m long in the Ceniza drainage (SSW). During 25-26 November ash plume from explosions rose 550 m and drifted 10 km W and SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 November-19 November 2013

On 18 November INSIVUMEH reported that during the previous week explosions from Fuego produced ash plumes that rose 450-750 m and drifted W and SW. Some of the explosions generated rumbling noises, shock waves detected within 15 km, and rattled structures in Panimaché (8 km SW), Panimaché II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), and Sangre de Cristo (8 km WSW). A 600-m-long lava flow was active on the SE flank, and block avalanches that descended the Ceniza drainage (SSW) reached vegetated areas. Ashfall was reported in Panimaché, Morelia, and Sangre de Cristo.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 October-5 November 2013

INSIVUMEH reported that on 4 November, there was an increase in moderate and strong explosions generating plumes of ash up to 4,500 m a.s.l. The plume extended 10 km and drifted S and SW. Rumbling sounds were strong enough to shake zinc roofs and windows in the towns of Panimaché, Morelia, and Panimaché II. Weak degassing sounds were continuous and resembled the sound of a locomotive train. Pulses of incandescent ejections reached 125-200 m above the summit and caused weak-to-moderate avalanches within the crater. A lava flow that moved into the Trinidad drainage extended 100 m and also generated avalanches. Within the Ceniza drainage, incandescent avalanches traveled ~500 m. CONRED reiterated that the Alert Level remained at Yellow.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 September-17 September 2013

INSIVUMEH reported that during 10-11 September explosions from Fuego generated ash plumes that drifted W and NW. Ejected material formed avalanches within the crater. On 10 September lahars that descended the Taniluya (SW) drainage were 15-20 m wide, 1-2 m deep, and carried tree trunks. The lahars blocked roads in Panimache I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW) for two hours. The next day lahars descended the Las Lajas and El Jute drainages (SE); they were 30 m wide, 4 m deep, and carried 2-m-diameter blocks, branches, and tree trunks.

Explosions during 11-12 September produced rumbling sounds and ash plumes that rose 500 m. Incandescent material was ejected 100 m and formed avalanches on the crater rim. A 150-m-long lava flow was active in Ceniza (SSW) drainage. During 12-13 September ash plumes from explosions rose 200-400 m and drifted W and NE. Avalanches from ejected material again formed around the crater. Explosions during 14-15 September generated ash plumes that rose 850 m and drifted 10-12 km W and SW. The explosions produced shock waves that rattled structures in villages within10 km of Fuego. Block avalanches descended Ceniza drainage. During 15-16 September explosions generated ash plumes that rose 550 m and drifted SW, and ejected incandescent material 75-100 m high. Ash fell at the observatory.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


4 September-10 September 2013

INSIVUMEH reported that during 4-6 September explosions from Fuego generated ash plumes that rose 800-850 m and drifted 10-12 km W and SW. Block avalanches descended the Ceniza (SSW) drainage. During 5-6 September explosions produced shock waves that rattled structures in villages 10 km away.

On 6 September the number and magnitude of explosions increased; rumbling and shock waves were reported 12 km away. Ash plumes rose 750 m and drifted 10 km W and SW. During 7-10 September explosions generated ash plumes that rose 250-400 m; plumes drifted 7 km W and NW on 7 September. Incandescent material was ejected 100 m high and then formed small avalanches. On 9 September heavy rain was followed by lahars in the Las Lajas and El Jute drainages which carried blocks 2 m in diameter. During 9-10 September ash plumes drifted 6 km E and SE.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 August-3 September 2013

INSIVUMEH reported that during 28-31 August explosions from Fuego generated ash plumes that rose 450-550 m and drifted 8-10 km W and NW. During 28-29 August incandescent material was ejected 150 m high, and white plumes rose 350 m and drifted NW. During 30-31 August rumbling was heard 15 km away. Lava flows 200 m long were active in the Trinidad drainage on the S flank and produced avalanches. In a special bulletin on 2 September, INSIVUMEH reported that a series of pyroclastic flows descended the Ceniza (SSW) drainage, reaching the base of the volcano. Ash plumes rose 3 km and drifted E, S, W, and NW. During the night lava from the crater flowed 300-400 m down the Ceniza drainage. Explosions were heard, but cloud cover prevented observations through the morning of 3 September.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 August-27 August 2013

INSIVUMEH reported that during 22 and 24-25 August explosions from Fuego generated ash plumes that rose 300-500 m and drifted W and NW. Degassing and rumbling sounds were also reported. Active lava flows were 300 and 500 m long in the Taniluyá (SW) and Ceniza (SSW) drainages, respectively. On 23 August lava extrusion increased. Ash plumes rose about 1 km and drifted 12 km W. Fourteen explosions during 26-27 August produced ash plumes that rose 200-500 m and drifted 8 km. Incandescent material was ejected 150 m high, and avalanches from the crater descended the flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 August-20 August 2013

INSIVUMEH reported that explosions from Fuego during 13-14 August generated ash plumes that drifted 10 km W and SW. Three lava flows were active; one of the flows traveled SW. Five explosions during 14-15 August ejected incandescent material 100 m high, and generated ash plumes that rose 300 m and drifted 6 km. Lava flows were 150 and 300 m long in the Taniluya (SW) and Ceniza (SSW) drainages, respectively. The next day explosions produced ash plumes that rose 550 m and drifted 10 km W. On 17 August 30-m-wide lahars carrying blocks traveled down the Las Lajas, Ceniza, and El Jute (SE) drainages. During 17-18 August explosions that were heard generated ash plumes that rose 200-300 m and drifted 7 km W. Lava flows in the Taniluya and Ceniza drainages were each 400 m long.

During 18-19 August the flow rate increased; the lava flows were 600 and 800 m long in the Taniluya and Ceniza drainages, respectively. Incandescent blocks from the lava-flow fronts rolled down the flanks and reached vegetated areas. Explosions during 19-20 August ejected incandescent material as high as 150 m, and generated ash plumes that rose 400 m.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 July-9 July 2013

INSIVUMEH reported that explosions from Fuego during 3-9 July generated ash plumes that rose 100-750 m above the crater and drifted 4-10 km W and NW on most days. During 4-5 and 8-9 July shock waves vibrated structures in areas including Sangre de Cristo (8 km WSW), Panimaché (8 km SW), and Morelia (9 km SW). On 5 July lahars descended the Las Lajas and El Jute drainages (SE), carrying blocks up to 50 cm in diameter.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


26 June-2 July 2013

INSIVUMEH reported that explosions from Fuego on 26 June generated shock waves and ash plumes that rose 400 m and drifted SW. On 27 June explosions produced ash plumes that rose 550 m and drifted 10 km. Shock waves vibrated structures in areas including Sangre de Cristo (8 km WSW), Panimaché (8 km SW), and Morelia (9 km SW). Lahars descended the Las Lajas and El Jute drainages (SE), carrying blocks up to 1.5 m in diameter as well as tree trucks and branches.

On 28 June Vulcanian explosions produced shockwaves felt by local populations within 15 km. Explosions also generated ash plumes that rose 100-200 m and drifted W, and ejected incandescent tephra 150 m above the crater. Ashfall was reported in Panimaché, Morelia, and Sangre de Cristo. A lava flow was active on the flank. During 29 June-2 July explosions generated ash plumes that rose 500-600 m and mostly drifted W and NW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


5 June-11 June 2013

INSIVUMEH reported that during 5-8 June explosions at Fuego generated ash plumes that rose 200-500 m and drifted 4-6 km W and NW. The explosions produced weak rumbling, ejected incandescent material 100 m above the crater, and generated avalanches. On 8 June lahars descended the Las Lajas and El Jute drainages (SE), and the Ceniza drainage (SSW). During 9-11 June explosions produced ash plumes that rose 500-1,200 m and drifted 8-12 km W and NW. The explosions again produced rumbling, ejected incandescent material 150-300 m above the crater, and generated avalanches. Shock waves vibrated local structures during 8-9 June.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


29 May-4 June 2013

INSIVUMEH reported that rumbling and sounds resembling jet engines were heard from Fuego during 28-30 May; cloud cover often inhibited visual observations of the crater. On 29 May a lahar carrying blocks up to 50 cm in diameter traveled SE down the Las Lajas and El Jute drainages. On 30 May a plume was observed rising 200 m above the crater and drifting S. During 1-2 and 4 June explosions generated ash plumes that rose at most 800 m and drifted 5-8 km W and NW. Incandescent material was ejected 100 m above the crater and generated avalanches. On 2 June heavy rain caused lahars that traveled down the Ceniza drainage, carrying trees, logs, and blocks. On 3 June diffuse white plumes rose 200 m.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 May-21 May 2013

INSIVUMEH reported that during 16-17 May white plumes rose 300 m from Fuego’s crater and drifted W and SW. Explosions during 17 and 19-21 May generated ash plumes that rose 350-650 m and drifted 6 km W and SW. On 19 and 21 May explosions ejected incandescent material 100 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 April-30 April 2013

INSIVUMEH reported that during 23-26 April explosions from Fuego generated ash plumes that rose 250-600 m above the crater and drifted at most 10 km W, SW, S, and SE. Incandescent material was ejected 100-200 m above the crater. In a special bulletin on 25 April INSIVUMEH noted that the energy of the explosions had increased, producing rumblings and shock waves that vibrated structures in Panimaché, Morelia, and Sangre de Cristo, as far as 10 km S and SW. A 300-m-long lava flow was active on the S flank in the Trinidad drainage. On 26 April a lava flow in the Taniluya drainage (SW) traveled as far as 400 m. On 28 April activity again increased and 700-m-long lava flows were active in the Taniluya and Ceniza drainages. Incandescent block avalanches reached vegetated areas. Cloud cover prevented observations of the crater. On 29 April explosions generated ash plumes that rose 550 m above the crater and drifted 10 km SSW. Lava flows remained active.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 March-2 April 2013

INSIVUMEH reported that during 27 March-2 April explosions from Fuego generated rumbling noises, occasional shock waves, and ash plumes that rose 0.6-1.3 km above the crater and drifted 8-15 km W, SW, and S. Incandescent material was ejected 100-200 m above the crater. Ashfall was reported in Panimaché I and II (8 km SW), Morelia (9 km SW), and Hagia Sophia. Block avalanches descended the flanks and during 1-2 April reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 March-26 March 2013

In a special notice on 20 March, INSIVUMEH reported that lava fountains rising 300-400 m above Fuego's crater during the night had decreased along with seismicity and rumbling noises. A lava flow was 1.5 km long in the Ceniza drainage (SSW), and ash plumes drifted SE and S. Explosions during 20-21 and 25-26 March generated ash plumes that rose 0.6-1.2 km and drifted SE, S, and W. Incandescent material was ejected from the crater. Lava flows remained active in the Ceniza drainage and traveled 600 m SW down the Taniluya drainage. Explosions produced ash plumes that rose 400-800 m above the crater and drifted E and W during 21-22 March, rose 300-500 m and drifted 5 km W and NW during 23-24 March, and rose 450 m and drifted W and NW during 24-26 March, which caused ashfall in Panimache I and II (8 km SW), Morelia (9 km SW), and Hagia Sophia.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 March-19 March 2013

INSIVUMEH reported that during 13-18 March explosions from Fuego produced ash plumes that rose as high as 4.5 km above the crater, and drifted SW, W, NW, and NE, as far as 12 km. Explosions sometimes ejected incandescent material, generated rumbling noises, and produced shock waves. During 13-14 March ash fell in Panimache I and II (8 km SW) and shock waves vibrated structures. Ash again fell in the Panimache villages as well as in Morelia (9 km SW) during 14-15 March. Avalanches traveled SSW down the Ceniza drainage during 16-19 March.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


6 March-12 March 2013

INSIVUMEH reported that during 6-8 March rumbling noises from Fuego were reported and incandescent material was ejected 50-100 m above the crater. Avalanches traveled SSW down the Ceniza drainage during 6-7 March. Explosions during 8-11 March produced ash plumes that rose up to 450 m above the crater and drifted W, SW, S, SE, and E. During 11-12 March ash plumes drifted 10 km and produced ashfall in the Panimache villages (8 km SW) and Morelia (9 km SW). Lava flows were also observed.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 February-5 March 2013

INSIVUMEH reported that during 28 February-1 March explosions from Fuego produced ash plumes that rose less than 250 m and lava flows traveled 300 m S down the Trinidad drainage. Activity increased on 3 March characterized by Strombolian explosions, and lava flows that traveled 1.3 km down the Trinidad drainage and 200 m SW down the Taniluya drainage. Ash plumes rose almost 350 m above the crater and drifted 10 km S. The eruption ended the next day, after 52 hours of activity. White and blue fumarolic plumes rose from the crater. During 4-5 March incandescence 100 m above the crater was observed, and ash plumes rose 200 m and drifted E. Avalanches descended the Taniluya drainage.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 February-19 February 2013

INSIVUMEH reported that during 14-15 February white plumes rose 150 m above Fuego's crater and drifted W and NW. The lava flow traveled 500 m SSW down the Ceniza drainage and produced avalanches. Activity increased on the night of 16 February and was characterized by explosions, pyroclastic flows, and lava flows. A pyroclastic flow traveled 3 km down the Ceniza drainage. Ash plumes drifted 20 km W and SW, and produced ashfall in Panimache I and Panimache II (8 KM SW), Morelia (9 km SW), Santa Sofía (12 km SW), Sangre de Cristo (8 km WSW), and Yepocapa (8 km WNW). On 17 February collapses from the lava-flow fronts and pyroclastic flows were observed. Ash plumes rose 3 km and drifted 10 km W and SW. Seismicity decreased. According to the Washington VAAC ash plumes detected in satellite imagery drifted 19 km W, 10 km SW, and 5 km S. INSIVUMEH noted that lava effusion continued and ash fell on the flanks. On 18 February an explosion generated an ash plume that rose 2 km above the crater and drifted 10 km NE. Two other explosions produced ash plumes that rose 500-800 m. Avalanches traveled S and W.

Sources: Washington Volcanic Ash Advisory Center (VAAC); Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 January-8 January 2013

INSIVUMEH reported that during 3-8 January explosions from Fuego produced ash plumes that rose less than 350 m and drifted W and SW. Lava flows traveled 300-900 m SW down the Taniluya drainage. During 7-8 January explosions produced plumes that drifted 5 km SW. Incandescence emanated 100 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


12 December-18 December 2012

INSIVUMEH reported that during 12-14 December explosions from Fuego produced ash plumes that rose about 140-190 m and drifted SW. Incandescent lava flows traveled 150-200 m down the flanks. During 15-16 December lava flows traveled 200 m SW down the Taniluya drainage, producing incandescent block avalanches from the lava-flow fronts. Explosions during 17-18 December produced ash plumes that rose 400 m and drifted 7 km W and SW. Incandescence emanated 150 m above the crater. Blocks from lava-flow fronts in the Taniluya drainage rolled down the flanks, reaching vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


7 November-13 November 2012

INSIVUMEH reported that during 8-9 and 11-12 November explosions from Fuego ejected incandescent material 100-200 m above the lava dome, and produced ash plumes that rose 200-430 m and drifted W and SW. Avalanches were generated near the crater. During 8-9 and 11-13 November lava flows traveled 200-500 m SSW down the Ceniza drainage, producing incandescent block avalanches that reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


31 October-6 November 2012

INSIVUMEH reported that during 1-2 November white fumarolic plumes from Fuego rose 100 m and drifted SW. Explosions ejected incandescent material 100 m above the lava dome, and produced ash plumes that rose almost 500 m and drifted 10 km SW. A lava flow traveled 350 m SSW down the Ceniza drainage. On 3 November heavy rain caused lahars that traveled down the Ceniza drainage, carrying tree branches and 2-m-wide blocks. During 3-6 November explosions generate ash plumes that rose 150-450 m and drifted W and NW. Incandescent material was ejected 100 m above the crater and generated avalanches near the crater. A lava flow traveled 600-800 m down the Ceniza drainage, producing incandescent block avalanches that reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


17 October-23 October 2012

INSIVUMEH reported that during 17-19 and 21-23 October white fumarolic plumes from Fuego drifted S and SW. Explosions produced ash plumes that rose 240-640 m above the lava dome and drifted 7 km SW, W, and NW. A lava flow traveled 400-800 m down the Ceniza drainage, producing incandescent block avalanches that reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


10 October-16 October 2012

INSIVUMEH reported that during 10-11 October lava flows traveled 200 m down the Ceniza drainage, on Fuego's SSW flank, producing incandescent block avalanches from the flow front and steam-and-tephra plumes. On 12 October a lava flow on the S flank traveled 800 m. Explosions produced ash plumes that rose 500 m and drifted 10 km S. During 14-16 October explosions produced ash plumes that rose 400 m and drifted W and SW. A lava flow traveled 800 m down the Ceniza drainage, producing incandescent block avalanches that reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 October-9 October 2012

INSIVUMEH reported that on 3 October a hot lahar descended Fuego's Ceniza drainage (SSW), carrying logs, branches, and blocks. During 4-5 October explosions ejected incandescent tephra 75-150 m above the crater, producing ash plumes that rose 600-900 m and drifted 10 km N and NW. Explosions generated shock waves and vibrated houses in local communities. Avalanches descended the Ceniza and Taniluyá drainages (SSW).

On 7 October the seismic network detected increased activity characterized by tremor, low-frequency earthquakes, and a period of constant explosions. Rumbling was heard and shock waves were detected. Ashfall was reported in Panimache I and II (8 KM SW), Morelia (9 km SW), and Santa Sofia (12 km SW). Incandescent block avalanches originating from the crater descended the flanks. During 7-8 October explosions ejected incandescent tephra 75-150 m above the crater, and generated ash plumes that drifted 10 km S and SW. On 8 October a lava flow traveled 100 m down the Ceniza drainage, producing incandescent block avalanches from the flow front. Avalanches descended the Taniluyá drainage. Ashfall was reported in Panimache I and II, Morelia, and Asunción.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


26 September-2 October 2012

INSIVUMEH reported that during 26-27 September explosions from Fuego ejected incandescent tephra 75-150 m above the crater, and produced ash plumes that rose 500-800 m and drifted 7 km N and NW. A hot lahar descended the Ceniza drainage (SSW), carrying logs, branches, and blocks over 1.5 m in diameter. During 29 September-2 October explosions ejected incandescent tephra 200 m above the crater and produced ash plumes that rose 500-1,100 m. Shock waves were detected in areas 12-15 km away. Incandescent avalanches traveled 700 m down the flanks; during 1-2 October avalanches traveled S down the Santa Teresa drainage. Ashfall was reported at the observatory, and in Morelia (8 km SW) and Santa Sofia (12 km SE).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 September-25 September 2012

INSIVUMEH reported that during 19-21 September explosions from Fuego ejected incandescent material 100 m above the crater and produced ash plumes that rose 500-1,000 m. Incandescent avalanches traveled 600 m down the flanks. Ashfall was reported at the observatory, and in Morelia (8 km SW) and Santa Sofia (12 km SE). During 22-25 September explosions generated ash plumes that rose 300-800 m above the crater and drifted 6-10 km NE, N, and NW. Incandescent material was ejected 75-150 m above the crater, and avalanches descended the Ceniza and Taniluyá drainages (SSW).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


12 September-18 September 2012

In a special bulletin on 13 September, INSIVUMEH reported that activity at Fuego increased, starting the sixth eruption in 2012. Lava flows traveled 600 m down the Taniluyá drainage (SSW) and the Las Lajas drainage (SE), producing block avalanches that reached vegetated areas. Strombolian explosions generated ash plumes that rose 3 km above the crater and drifted SW and 12 km W. Ash fell in multiple areas, including the villages of Panimaché (8 km SW), Morelia (8 km SW), Santa Sofia (12 km SE), Sangre de Cristo (8 km WSW), Palo Verde, San Pedro Yepocapa (8 km NW), Santiago Atitlan (42 km NW), San Lucas Toliman (32 km NW), Mazatenango (68 km W), Suchitepéquez, Retalhuleu (86 km W), and Santa Lucia Cotzumalguapa (23 km SW). Explosions produced degassing sounds and rumbling noises, accompanied by shock waves that vibrated structures on the SW flank. Pyroclastic flows traveled down the Las Lajas and Ceniza (SSW) drainages, producing ash plumes. CONRED increased the Alert Level to Orange (third highest on a four-color scale). About 10,600 people evacuated from nearby communities including Yepocapa, San Juan Alotenango (9 km ENE), Sacatepéquez. Evacuation shelters were set up in Santa Lucia Cotzumalguapa.

Later that day seismicity decreased, ash plumes rose 300 m above the crater and drifted W and NW, fewer pyroclastic flows were observed, and the rate of explosions slowed. Ashfall was reported in Panimaché, Morelia, and Sangre de Cristo. Lava flows in the Ceniza drainage were 1 km long and 150 m wide, and in Las Lajas were 700 m long and 100 m wide. CONRED noted that residents began to return to their homes on 14 September.

During 14-18 September explosions generated rumbling noises; ash plumes that rose 400-900 m above the crater drifted 7-8 km W and SW, causing ashfall in Sangre de Cristo, Panimaché I, and Panimaché II. Lava flows were at most 1.2 km long in the Taniluyá drainage and 200 m long in the Ceniza drainage during 14-16 September; flows were not observed during 17-18 September.

Sources: Coordinadora Nacional para la Reducción de Desastres (CONRED); Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


5 September-11 September 2012

In a special bulletin on 4 September at 1700, INSIVUMEH reported that the eruption from Fuego that began 32 hours earlier had ended. During 6-11 September fumarolic plumes rose 100-150 m above the crater and drifted W and NW. Weak explosions generated ash plumes that rose 300-400 m above the crater and drifted W and NW. During 8-9 September incandescent tephra was ejected to a height of 100 m and caused avalanches in the Taniluyá and the Ceniza (SSW) drainages. A 10-20-m-wide lahar traveled SE down the Las Lajas drainage on 9 September, carrying tree trunks and blocks 1.5 m in diameter. During 10-11 September a lava flow traveled 100 m down the Taniluyá drainage.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


29 August-4 September 2012

INSIVUMEH reported that during 29-30 August lava flows from Fuego traveled 250 m down the Taniluyá drainage (SW), generating block avalanches that produced gray plumes and reached vegetated areas.

Seismicity increased on 3 September. During 3-4 September constant Strombolian explosions generated ash plumes that rose 900 m above the crater and drifted 8 km S and SW. The eruption was heard in areas 10 km away and vibrated structures in Panimaché (8 km SW), Morelia (8 km SW), and Santa Sofia (12 km SE). Lava was ejected 100 m high and spilled over the crater rim. Lava flows traveled 3 km down the Taniluyá and the Ceniza (SSW) drainages, producing block avalanches that again reached vegetated areas. A third lava flow descended the Las Lajas drainage (SE). Pyroclastic flows traveled SE. Ash plumes drifted 10-12 km S and SW, and produced ashfall in Panimaché, Morelia, Santa Lucía, Cotzumalguapa, Tierra Linda, and Popoya.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 August-28 August 2012

INSIVUMEH reported that on 22 August the seismic network at Fuego detected lahars that traveled SE down the Las Lajas and El Jute drainages. During 22-27 August lava flows traveled 150-300 m down the Taniluyá drainage (SW) and as far as 400 m down the Ceniza drainage (SSW), generating incandescent block avalanches that reached vegetated areas. Incandescent material was ejected 100 m above the crater. White plumes rose to low heights and drifted SW, W, and NW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 August-21 August 2012

INSIVUMEH reported that during 15-16 and 18-21 August lava flows from Fuego traveled 250-500 m down the Taniluyá drainage (SW), generating block avalanches that reached vegetated areas. On 17 August 20-m-wide lahars traveled SE down the Las Lajas and El Júte drainages, carrying blocks 1.5 m in diameter. Steam rose from the deposits in Las Lajas. Explosions were heard during 18-29 August but weather conditions prevented observations. Explosions during 19-21 August produced ash plumes that rose 100-300 m above the crater and drifted N, NW, W, and SW. Incandescent material was ejected 40-100 m above the crater at night. In a special report issued on 21 August, INSIVUMEH stated that seismicity had increased, along with degassing and rumbling sounds. Incandescent material was ejected 150 m above the crater, and lava flows traveled 500 m down the El Júte and Taniluyá drainages, generating block avalanches that reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 August-14 August 2012

INSIVUMEH reported that during 9-10 and 13-14 August explosions from Fuego produced ash plumes that rose 300-400 m above the crater and drifted NW and W. Degassing sounds were reported, and diffuse white plumes rose 100-150 m and drifted NE and NW. Lava flows traveled 200-250 m down the Taniluyá drainage (SW), generating block avalanches that reached vegetated areas. On 10 August lahars 25 m wide traveled SE down the Las Lajas and El Júte drainages carrying blocks 1-2 m in diameter. Explosions during 13-14 August ejected incandescent tephra 100 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 August-7 August 2012

In a special bulletin on 3 August, INSIVUMEH reported a new phase of activity at Fuego, characterized by increased seismicity and degassing sounds. Incandescent tephra was ejected 200 m high and a lava flow traveled 500 m down the SW flank into the Taniluya drainage. Pyroclastic flows likely descended the SE and SW flanks. During 4-7 August explosions produced ash plumes that rose 200-400 m above the crater and drifted NW and W. Lava flows traveled 250-300 m down the Taniluyá drainage. Detached blocks from the lava-flow front traveled down the flanks to the vegetated area. Blocks also traveled down the Ceniza drainage (SSW). At night during 5-6 August explosions ejected incandescent tephra 100 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 July-31 July 2012

INSIVUMEH reported that during 26-27 and 29-31 July explosions from Fuego produced ash plumes that rose 200-500 m above the crater and drifted NW, W, and SW. Fumarolic plumes drifted the same direction. Explosions ejected incandescent tephra 100 m above the crater. Lava flows traveled 300 m down the Taniluyá drainage (SW) and 150 m down the Ceniza drainage (SSW); detached blocks from both lava-flow fronts produced incandescent avalanches.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 July-24 July 2012

INSIVUMEH reported that during 20-24 July explosions from Fuego produced ash plumes that rose 200-400 m above the crater and drifted W and NW. Fumarolic plumes drifted the same direction. Glow radiated 100-150 m above the crater. Lava flows traveled 200-250 m down the Taniluyá (SW) drainage; detached blocks from the lava-flow fronts produced incandescent avalanches.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 July-17 July 2012

INSIVUMEH reported that on 10 July lahars traveled SE down Fuego's Las Lajas and El Jute drainages carrying blocks 1-1.5 m in diameter. The lahar in Las Lajas was hot and had a sulfur odor. During 10-12 July explosions from Fuego produced ash plumes that rose 150-800 m above the crater and drifted W. On 11 July ashfall was reported in Sangre de Cristo (8 km WSW) and surrounding areas. Tephra avalanches descended the Ceniza (SSW) drainage. During 16-17 July explosions generated ash plumes that rose 200-600 m above the crater and drifted 10 km S and SW. Incandescence emanated from the crater and avalanches descended the Taniluyá (SW) and Ceniza (SSW) drainages.

In a special bulletin on 17 July, INSIVUMEH reported that seismic patterns indicated the beginning of a new phase of activity; avalanches on the S and SW flanks were constantly active, and a new lava flow emerged on the SW flank that traveled 200 m and produced blocks that rolled SW down the Taniluya drainage.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


4 July-10 July 2012

INSIVUMEH reported that during 4-6 July explosions from Fuego produced ash plumes that rose 400-800 m above the crater and drifted W. Rumbling sounds were reported and tephra avalanches descended the S flank. During 7-8 July rumbling and degassing sounds were reported. Although cloud cover mostly prevented observations, a weak plume was noted rising 200-300 m above the crater and drifting NE. Ash fell in Yepocapa (8 km WNW), and on the La Conchita and Monteclaro ranches. Small tephra avalanchas descended the Taniluyá (SW) and Ceniza (SSW) drainages. During 8-9 July a series of seven explosions produced ash plumes that rose 300-900 m above the crater and drifted 10 km W, again causing ashfall in Yepocapa, La Conchita, Monte llano, and Sangre de Cristo (8 km WSW). Explosions on 10 July produced ash plumes that rose 300-600 m above the crater and drifted W. Incandescence rose above the crater during 8-10 July.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 June-3 July 2012

INSIVUMEH reported that during 28-29 June activity at Fuego increased; explosions produced ash plumes that rose 500-600 m above the crater and drifted SW. Pulses of incandescence rose 200 m and tephra avalanches descended the Ceniza drainage (SSW). According to Coordinadora Nacional para la Reducción de Desastres (CONRED) on 1 July, seismicity increased and rumbling sounds were audible in areas up to 10 km away. A lava flow 700 m long was active in the Taniluya drainage on the SW flank. In a 2 July report, INSIVUMEH noted that the lava flow on the SW flank was 1,700 m long. Ash plumes rose 500 m above the crater and drifted 10 km W. The seismic network recorded continuous tremor. During 2-3 July explosions produced ash plumes that rose 400 m above the crater and drifted W. A lava flow traveled 400 m down the Taniluya drainage, and blocks from the flows reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 June-26 June 2012

INSIVUMEH reported that during 21-22 June weather conditions often prevented views of Fuego, however incandescence was observed emanating 150 m above the crater and an explosion produced an ash plume that rose 400 m. A lava flow traveled 1.3 km SSW down the Ceniza drainage and started a fire in a wooded area. Almost constant degassing on 21 June was heard at the Observatorio del Volcán de Fuego (OVFGO) and detected by the seismic network. During 24-26 June explosions generated ash plumes that rose 200-500 m above the crater. Incandescence from the crater was observed and block avalanches descended the flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 June-19 June 2012

INSIVUMEH reported that during 14-15 and 17-18 June explosions from Fuego produced ash plumes that rose 300-800 m above the crater and drifted WSW, E, and NE. Explosions generated rumbling sounds and shock waves detected in areas as far as 6 km away. Tephra avalanches descended the SW flank, into the Ceniza drainage, and lava flowed 200 m SW, into the Taniluya drainage. Pulses of incandescence rose 50-75 m above the crater. During 18-19 June lava flows advanced 50 m and block avalanches reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


6 June-12 June 2012

INSIVUMEH reported that on 6 June lahars descended Fuego's El Jute (SE), Las Lajas (SE), Ceniza (SSW), Santa Teresa (S), and Taniluyá (SW) drainages, and destroyed roads in Yepocapa (8 km WNW). During 6-7 June explosions produced ash plumes that rose 200-500 m above the crater and drifted N, and 12 km S and SW. Lava flows on the SE flank were about 800-900 m long in the Las Lajas drainage, 600 m long in the El Jute drainage, and 250 m long on the SW flank, and produced blocks that rolled and reached vegetated areas. The explosions were accompanied by rumbling sounds and shock waves that were detected in areas 10 km away, including Panimaché and Morelia (~8 km SW).

During 10-11 June an ash plume rose 1.5 km above the crater and drifted 15 km W and NW. Ashfall was reported in Panimaché I and II, Sangre de Cristo (8 km WSW), Yepocápa, and other villages nearby. Lava flows traveled 1.6 km down Taniluyá drainage, 1 km down the Ceniza drainage, and 1.5 km down Las Lajas. Pyroclastic flows descended Las Lajas. During 11-12 June explosions generated ash plumes that rose 300 m above the crater and drifted W. Lava flows traveled 300 m down the Taniluyá drainage. Incandescence rose 100 m.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 May-5 June 2012

INSIVUMEH reported that on 1 June hot lahars traveled SE down Fuego's Las Lajas and El Jute drainages carrying blocks 2 m in diameter. During 3-5 June explosions produced ash plumes that rose 500-1,000 m above the crater and drifted W and S. Pulses of incandescence from the crater was observed as well as avalanches on the W flank. Lava flows traveled 700 m down Taniluyá Canyon drainage and 1 km down Las Lajas. During 4-5 June seismicity increased and the lava flow in Las Lajas reached 1.2 km long. Explosions produced ash plumes that rose 600-800 m above the crater and drifted 7 km SW. Shock waves were detected up to 7 km away.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 May-29 May 2012

INSIVUMEH reported that during 22-23 May explosions from Fuego produced ash plumes that rose 700 m above the crater and drifted W and SW. Explosions produced shock waves and rumbling noises, and avalanches descended the SW flank towards the Ceniza drainage. Seismic data suggested that on 25 May lava was emitted in the crater, although lava flows were not observed the previous few days. Plumes rose 2 km above the crater and drifted SE, SW, and W. Ashfall was reported in Sangre de Cristo (8 km WSW), Yepocapa (8 km WNW), and in the department of Chimaltenango (21 km NNE). A pyroclastic flow traveled SW down the Las Lajas drainage. During 26-29 May explosions produced ash plumes that rose as high as 1 km above the crater and drifted N, NE, S, and SE. A lava flow traveled 200 m SW and avalanches from the lava-flow front traveled 300 m during 26-27 May. Pulses of incandescence 100 m high were observed during 28-29 May.

Sources: Coordinadora Nacional para la Reducción de Desastres (CONRED); Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 May-22 May 2012

On 19 May seismicity at Fuego increased and explosions were heard at 5-10 minute intervals. A 600-m-long lava flow descended the W flank, and a 1-km-long and 20-m-wide lava flow descended the E flank, reaching the base of the volcano. Explosions ejected incandescent tephra 400 m above the crater, and produced ash plumes that rose 5 km above the crater and drifted 30 km S and SW. Coordinadora Nacional para la Reducción de Desastres (CONRED) raised the Alert Level to Orange (the second highest level on a 4-color scale). Pyroclastic flows also descended the flanks, prompting authorities to restrict passage on part of a highway. Ash plumes from the pyroclastic flows rose 3 km above the crater. Ashfall was reported in Morelia (7 km SW), Panimaché I and II (9 km SW), Sangre de Cristo (8 km WSW), and Yepocapa (8 km WNW). Thirteen people from El Porvenir in Alotenango (8 km ENE) evacuated to local shelters. Visual observations and seismicity indicated that activity decreased later that day.

On 20 May a few explosions generated ash plumes that rose 500 m above the crater and drifted 8 km SW. The next day cloud cover prevented observations; however explosions, rumbling, and degassing sounds were reported. On 22 May explosions generated ash plumes that rose as high as 1 km and drifted 10 km S and SE. Rumbling was heard and shock waves were detected. The lava flows were inactive and only incandescence from block avalanches was observed.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


4 April-10 April 2012

INSIVUMEH reported that during 9-10 April explosions from Fuego produced ash plumes that rose 100-900 m above the crater and drifted 10-15 km E and SE. Explosions produced shock waves detected within 8 km of the volcano. Avalanches descended the flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 March-3 April 2012

INSIVUMEH reported that during 31 March-1 April and 3-4 April explosions from Fuego produced ash plumes that rose 500-800 m above the crater and drifted 10 km W and NW. During the night lava fountains rose 100-150 m above the crater and formed avalanches that traveled towards the Río Cenizas drainage. Based on analysis of satellite imagery, the Washington VAAC reported that on 1 April an ash plume drifted 13 km WSW and a well-defined thermal anomaly was observed.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


29 February-6 March 2012

INSIVUMEH reported that during 1-2 March explosions from Fuego produced ash plumes that rose 600 m above the crater and drifted 15 km W and SW. Ashfall was reported in Yepocapa (W), Sangre de Cristo (W), and Panimache II (SW). Some explosions produced rumbling and degassing sounds. A 300-m-long lava flow descended the SW flank and produced block avalanches that reached vegetated areas. On 4 March the number of explosions increased to about 4-5 per hour. Explosions generated ash plumes that rose 600 m above the crater and drifted 12 km SSW. Rumbling sounds were heard 7 km away.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 February-7 February 2012

INSIVUMEH reported that during 1-3 and on 6 February explosions from Fuego generated ash plumes that rose 400-900 m above the crater; the plumes drifted about 12 km S and SW on 1 February and to the SSW during 2-3 February. On 1 February rumbling noises were heard, incandescence material rose as high as 100 m above the crater, and block avalanches descended the S flank. A new 200-m-long lava flow descended the SW flank into the Taniluya drainage and block avalanches reached vegetation during 2-3 February. On 6 February the lava flow descended towards the Ceniza drainage and block avalanches again reached vegetation. Strong winds caused re-suspended ash to rise 1 km high and drift several kilometers W and S during 1-3 February.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 January-24 January 2012

INSIVUMEH reported that during 18-19 and 23-24 January explosions from Fuego generated ash plumes that rose 200-700 m above the crater; the plumes drifted 8-15 km S, SW, and W. During 18-19 January incandescent material rose as high as 100 m above the crater and at night on 23 January incandescent explosions were observed. Block avalanches descended the S flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 January-17 January 2012

INSIVUMEH reported that during 11-13 and on 16 January explosions from Fuego generated ash plumes that rose 400-1,000 m above the crater; the plumes drifted 10-15 km in multiple directions. Explosions generated shock waves and rumbling sounds that were detected to the SW, and windows and roofs vibrated in nearby villages. Avalanches traveled SW into the Ceniza drainage and on the W, S, and SW flanks. At night on 13 and 16 January incandescence emanated from the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


4 January-10 January 2012

INSIVUMEH reported that on 6 and 10 January weak explosions from Fuego generated ash plumes that rose 300-600 m above the crater and drifted 10 km WNW and 15 km SW, respectively. Rumbling noises were detected several kilometers away. Incandescence emanated from the crater at night and avalanches descended the S, SW, and SE flanks. Based on information from satellite observations and INSIVUMEH, the Washington VAAC reported that an ash plume drifted SE and later dispersed on 3 January.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


28 December-3 January 2012

INSIVUMEH reported that during 29 December-3 January explosions from Fuego generated ash plumes that rose 400-800 m above the crater; the plumes usually drifted SSW and WSW, but on 30 December they drifted 10 km E and NW. During the week explosions generated shock waves and rumbling sounds that were detected 10 km away. House windows and roofs vibrated in nearby villages. Incandescence emanated from the crater at night, and avalanches traveled SW into the Taniluyá and Ceniza drainages, and S in the Santa Teresa drainage during 29 December-2 January. On 3 January the wind lifted ash to an altitude of 500 m. Based on information from satellite observations, the Washington VAAC reported that a possible ash plume drifted SE on 3 January. That same day, information from INSIVUMEH and satellite imagery indicated small emissions that rose to an altitude of 4.9 km (16,000 ft) a.s.l and drifted SE.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


21 December-27 December 2011

INSIVUMEH reported that during 21-27 December explosions from Fuego generated ash plumes that rose 200-800 m above the crater; the plumes drifted 10-12 km W, NW, SW, and S during 21-23 and 26-27 December. During 21-23 and 26-27 December explosions generated shock waves and rumbling sounds that were detected 12 km away. House windows and roofs vibrated in nearby villages on 27 December. Incandescence emanated from the crater at night, and avalanches traveled SW into the Taniluyá and Ceniza drainages, and S in the Santa Teresa drainage. Based on satellite observations, the Washington VAAC reported that a gas plume with possible ash drifted 9 km S on 24 December.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


7 December-13 December 2011

INSIVUMEH reported that on 9 and 13 December explosions from Fuego produced rumbling sounds and ash plumes that rose 300-600 m above the crater and drifted W, SW, and S. Block avalanches descended the SW flank toward the Ceniza drainage.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 November-6 December 2011

INSIVUMEH reported that on 1 December explosions from Fuego produced ash plumes that rose 800 m above the crater and drifted to the S. Avalanches descended toward Ash Creek. During 5-6 December ash plumes rose to an altitudes of 400-500 m above the crater and drifted to the W. A 150-m-long lava flow descended toward Ash Creek and avalanches reached vegetated areas.

Based on information from INSIVUMEH, the Washington VAAC reported gas and ash emissions on 2 December and a possible ash plume rose to an altitude of km (10,000 ft) a.s.l. on 6 December.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


9 November-15 November 2011

INSIVUMEH reported that activity at Fuego increased during 8-9 November. Explosions produced shock waves that were detected up to 15 km away, rumbling sounds, and ash plumes that rose 1.5-2 km above the crater and drifted 20 km SW. Ash fell on the SW flank in Panimaché (6 km SW), Morelia (7 km SW), Sangre de Cristo (8 km WSW), and Santa Sofía. Block avalanches descended the flanks. During 9-10 November explosions generated ash plumes that rose 600-800 m above the crater and drifted 10 km S and SW. Avalanches descended the SW flank towards the Taniluya and Ceniza drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 October-25 October 2011

INSIVUMEH reported that during 20-21 October explosions from Fuego produced shock waves that were detected nearby, rumbling sounds, and ash plumes that rose 500 m above the crater and drifted W. Incandescence emanated from the crater at night, and avalanches traveled SW into the Taniluyá, Ceniza, and Trinidad drainages. On 23 October, the Washington VAAC reported that an ash plume was observed in satellite imagery.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


12 October-18 October 2011

INSIVUMEH reported that during 14-15 October explosions from Fuego produced shock waves that were detected nearby, rumbling sounds, and ash plumes that rose 700 m above the crater and drifted S. A small avalanche traveled S in the Santa Teresa drainage. Cloud cover prevented visual observations during 16-18 October; however, explosions and block avalanches were heard.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 September-20 September 2011

INSIVUMEH reported that during 13-14 September explosions from Fuego produced ash plumes that rose 800 m above the crater. The explosions occasionally produced shock waves detected 7 km away. Incandescence at night emanated from the crater and from avalanches on the flanks. During 15-16 September cloud cover prevented observations of the crater but explosions were heard. Block avalanches descended the flanks and an ash plume drifted 7 km W. During 19-20 September explosions produced ash plumes that rose 500 m above the crater and drifted W.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 July-19 July 2011

INSIVUMEH reported that during 13-14 July explosions from Fuego produced ash plumes that rose 700 m above the crater and drifted W. Incandescence at night emanated from a 100-m-long lava flow on the S flank. Block avalanches reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 June-28 June 2011

INSIVUMEH reported that during 23-24 June explosions from Fuego produced ash plumes that rose 150-200 m above the crater and drifted W. Incandescent bursts rose 100 m above the crater. During 23-24 and 27-28 June lava flows traveled 200 m down the Ceniza drainage to the SW and detached blocks reached vegetated areas.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 April-3 May 2011

INSIVUMEH reported that during 28-29 April explosions from Fuego produced ash plumes that rose 300-600 m above the crater and drifted SW and S. The explosions sometimes produced shock waves. Lava flows traveled 200 m S and block avalanches descended the Ceniza and Santa Teresa drainages. Explosions during 1-2 May produced ash plumes that rose 200 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 March-5 April 2011

INSIVUMEH reported that during 30-31 March and 4-5 April explosions from Fuego produced ash plumes that rose 200-700 m above the crater and drifted W, SW, and S. Lava flows traveled almost 200 m SW down the Ceniza drainage and produced block avalanches from lava-flow fronts. Crater incandescence was observed at night.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 March-22 March 2011

INSIVUMEH reported that during 17-18 and 20-22 March explosions from Fuego produced ash plumes that rose 300-600 m above the crater and drifted 5-8 km W, SW, and S. Incandescent material was ejected as high as 100 m above the crater. Avalanches traveled SW, into the Taniluyá, Santa Teresa, Ceniza, and Trinidad drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 February-1 March 2011

INSIVUMEH reported that during 24-25 and 27-28 February explosions from Fuego produced ash plumes that rose 500-700 m above the crater and drifted W and SW. Incandescent material was ejected as high as 100 m above the crater. Avalanches traveled SW, descending the Taniluyá, Ceniza, and Trinidad drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 February-22 February 2011

INSIVUMEH reported that during 16-17 and 20-22 February explosions from Fuego produced ash plumes that rose 300-800 m above the crater. Some plumes drifted E. Incandescent material was ejected as high as 100 m above the crater. Avalanches traveled E as well as SW, descending the Taniluyá, Santa Teresa, Ceniza, and Trinidad drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 February-15 February 2011

INSIVUMEH reported that during 9-10 and 13-14 February explosions from Fuego produced ash plumes that rose 300-800 m above the crater and drifted W, NW, N, and NE. The explosions generated shock waves that rattled structures in Panimaché and Sangre de Cristo. Crater incandescence was observed at night and avalanches descended the flanks. Fine ashfall was reported in communities downwind during 9-10 February, including Panimaché I and II (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 February-8 February 2011

INSIVUMEH reported that during 2-3 February Fuego produced 27 explosions with ash plumes that rose 300-500 m above the crater and drifted 7 km W and SW. The explosions generated shock waves detected as far away as 5 km W and SW, in Sangre de Cristo, Panimache I and II, and Morelia. Block avalanches descended the Santa Teresa, Taniluyá, Cenizas, and Trinidad drainages to the SW. During 6-8 February explosions produced ash plumes that rose 500 m above the crater and drifted W and SW. At night incandescence was observed emanating from the crater and explosions sometimes ejected incandescent material 100 m above the crater rim.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 January-25 January 2011

INSIVUMEH reported that during 19-20 and 23-24 January explosions from Fuego produced ash plumes that rose 500-800 m above the crater and drifted W, NW, and S. Incandescent material was ejected as high as 100 m above the crater. Rumbling and degassing sounds were noted, and avalanches descended a few drainages.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


12 January-18 January 2011

On 10 January, INSIVUMEH reported an increase in the number and magnitude of explosions from Fuego since mid-December. During the previous three days explosions had produced ash plumes that rose 1 km above the crater and drifted 25 km mainly S and SW, and remained in the atmosphere for several hours. INSIVUMEH recommended that civil aviation authorities restrict flying within 25 km S and SW of Fuego. During 13-14 and 16-18 January explosions produced ash plumes that rose 200-500 m above the crater and drifted SW, E, and NE. Rumbling was heard and shock waves were detected. At night during 13-14 January, explosions ejected incandescent material as high as 75 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


5 January-11 January 2011

INSIVUMEH reported that during 5-6 January explosions from Fuego produced ash plumes that rose 500-800 m above the crater and drifted 10 km S and SW. The explosions caused windows and roofs to rattle in areas 6 km away. Fine ashfall was reported in communities downwind including Panimaché (6 km SW), Morelia (7 km SW), and Yepocapa (8 km WNW). Incandescence from the crater was observed at night. On 8 January, the Washington VAAC reported multiple gas-and-ash plumes that rose to an altitude of 5.2 km (17,000 ft) a.s.l. were observed in satellite imagery. During 10-11 January INSIVUMEH again reported that explosions produced ash plumes that rose 500-800 m above the crater and shock waves that were detected as far away as 7 km. Plumes drifted 15 km W and block avalanches descended a few drainages.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


29 December-4 January 2011

INSIVUMEH reported that during 29-30 December explosions from Fuego, almost constant at times, produced dense ash plumes that rose 600-800 m above the crater and drifted 8 km W and SW. Avalanches occurred on the flanks. The Washington VAAC reported that several small emissions observed in satellite imagery drifted W on 1 January. INSIVUMEH noted that during 3-4 January explosions generated ash plumes that rose 800-1,000 m above the crater and fanned out towards the S and SW. The plumes drifted almost 15 km and caused ashfall in areas downwind, including Panimaché (6 km SW), Morelia (7 km SW), and Santa Sofia (12 km SW). Incandescence from the crater was observed at night.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


22 December-28 December 2010

On 22 December, the Washington VAAC reported that an ash plume from Fuego observed in satellite imagery drifted 28 km NW. INSIVUMEH reported that on 23 December explosions produced ash plumes that rose 600-1,200 m above the crater and drifted 10-15 km SE. Explosions the next day generated ash plumes 400 m above the crater. Incandescent material was ejected 100 m above the crater at night during 27-28 December. On 28 December ash plumes from explosions rose as high as 500 m above the crater and drifted more than 5 km S and SW. Avalanches descended multiple drainages.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


15 December-21 December 2010

On 17 December, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 300-800 m above the crater and drifted E and SE. Later that day the number of explosions increased, occurring at a rate of 12-15 per hour. Ash plumes rose 500-900 m above the crater and drifted E and NE. Ashfall was reported in Antigua Guatemala, 18 km NE, and San Juan Alotenango, 9 km ENE. On 20 December, weak explosions generated ash plumes that rose 500 m above the crater and drifted W and NW, and occasional rumbling noises.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 December-14 December 2010

On 8 December, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 500 m above the crater and drifted S and SW. The Washington VAAC stated that on 10 December an ash plume was observed in satellite imagery. During 13-14 December, INSIVUMEH again reported explosions; ash plumes rose 400-900 m above the crater and drifted S and SE. Some of the explosions were heard 10 km away and generated shock waves that rattled structures nearby, including Panimache (8 km SW), Morelia (10 km SW), Santa Sofía, and Yucales (12 km SW). Avalanches descended the S and W flanks. At night, incandescent material was ejected 100 m high.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


1 December-7 December 2010

Based on analysis of satellite imagery, the Washington VAAC reported that on 4 December a diffuse plume of gas and possibly ash drifted SW. On 6 December, INSIVUMEH reported that explosions produced ash plumes that rose 900 m above the crater and drifted 6 km SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


17 November-23 November 2010

During 18-22 November, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose as high as 1 km above the crater and drifted S, SW, and W. Incandescent material was ejected 100 m above the crater and avalanches occurred. Ashfall was reported in areas downwind, including in villages 10 km W. Some explosions were accompanied by rumbling noises and shock waves detected as far away as 8 km.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


10 November-16 November 2010

On 12 November, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 800 m above the crater and drifted S and SW. At night, incandescent material was ejected to low heights above the crater. Avalanches occurred around the crater rim. Based on analyses of satellite imagery, the Washington VAAC reported that during 12-13 November ash plumes drifted as far as 37 km SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


27 October-2 November 2010

During 28-29 October, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 300-600 m above the crater. Incandescent material was ejected 75 m above the crater, and rumbling and degassing sounds were occasionally heard. Avalanches descended the W flank. On 18 October, ashfall was reported in Sangre de Cristo, 10 km WSW. Based on analyses of satellite imagery, the Washington VAAC reported that on 31 October an ash cloud was detected up to 20 km W of Fuego.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


20 October-26 October 2010

During 21-22 and 26 October, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 500-700 m above the SW crater. Rumbling and degassing sounds were occasionally heard, and incandescence was observed at night. Block avalanches occurred on the flanks. On 26 October, ash plumes drifted N and NW, and incandescent material was ejected 75 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


29 September-5 October 2010

INSIVUMEH reported that on 2 October a seismic station near Fuego recorded some explosions and a possible lahar that traveled SE. Weather prevented visual observations. During 4-5 October, explosions ejected incandescent material above the crater and produced ash plumes that rose 500-700 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 August-17 August 2010

During 12-17 August, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted W and NW. Rumbling and "degassing" sounds were associated with the explosions. At night during 15-16 August explosions ejected incandescent material 100 m above the crater. On 17 August blocks descended the S flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 July-20 July 2010

INSIVUMEH reported on 19 July that six explosions from Fuego produced ash plumes that rose to an altitude of 4.4 km (14,400 ft) a.s.l. and drifted W and SW. Rumbling and "degassing" sounds were associated with the explosions. Light ashfall was reported in Sangre de Cristo, 10 km WSW. The seismic network had recorded a total of 17 explosions within the previous 24 hours.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 June-15 June 2010

INSIVUMEH reported that during 10-11 June multiple explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.3 km (13,500-14,100 ft) a.s.l. and drifted NW. Rumbling and "degassing" sounds were associated with the explosions. Occasionally incandescent material was ejected as high as 75 m above the crater and avalanches descended the flanks. Fine ashfall was reported in Sangre de Cristo, 10 km WSW. During a period of increased activity on 11 June, shock waves were detected as far away as 5 km.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


26 May-1 June 2010

INSIVUMEH reported on 29 May that abundant rains from tropical storm Agatha triggered lahars in ravines to Fuego's SW and SE.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 May-25 May 2010

On 20 May, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l. and drifted SW. Incandescent material was ejected to heights of 100 m and avalanches descended the S and W flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 April-27 April 2010

On 26 April, INSIVUMEH reported that explosions from Fuego produced gray plumes that rose to altitudes of 4.3-4.6 km (14,100-15,100 ft) a.s.l. and drifted E. A few of the explosions produced avalanches around the volcano, and rumbling sounds were heard.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 February-2 March 2010

On 26 February and 2 March, INSIVUMEH reported that explosions from Fuego produced gray plumes that rose to altitudes of 4.1-4.5 km (13,500-14,800 ft) a.s.l. and drifted E and NE. Avalanches descended the S and W flanks. Weak incandescence emanated from the crater. On 2 March, ash fell in areas downwind.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 January-26 January 2010

On 22 January, INSIVUMEH reported that explosions from Fuego produced gray plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l. and drifted 5-12 km SW. Incandescent material was ejected to heights of 75 m and avalanches descended the flanks. Based on analyses of satellite imagery, the Washington VAAC reported that on 25 January a dense ash cloud drifted 15 km NW. The next day an ash cloud drifted 11 km W.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


6 January-12 January 2010

Based on analyses of satellite imagery, the Washington VAAC reported that on 6 January an ash plume from Fuego drifted 45 km SE. On 8, 11, and 12 January, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4-4.7 km (13,000-15,400 ft) a.s.l. Plumes drifted as far as 10 km in multiple directions, causing ashfall in some areas. Incandescent material was ejected to heights up to 75 m. Some explosions were accompanied by rumbling noises and shock waves that rattled structures up to 7 km away. Avalanches descended the flanks.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


9 December-15 December 2009

On 11, 14, and 15 December, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted 8-12 km W and SW. Incandescence from the main crater and rumbling noises were noted. Avalanches descended the S and W flanks. Based on analyses of satellite imagery, the Washington VAAC reported that on 12 December a gas-and-ash plume drifted 20 km W. On 15 December, ashfall was reported in areas SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


2 December-8 December 2009

On 4 December, INSIVUMEH reported that multiple explosions produced ash plumes that rose to altitudes of 4.2-4.7 km (13,800-15,400 ft) a.s.l. and drifted 15-18 km W. Ashfall was reported in communities downwind. Rumbling noises and incandescent block avalanches were also noted.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 November-1 December 2009

Based on analyses of satellite imagery, the Washington VAAC reported that on 29 November a small plume from Fuego, possibly containing ash, drifted 10 km SW. A thermal anomaly was also detected. On 30 November and 1 December, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.3-4.7 km (14,100-15,400 ft) a.s.l. and drifted 8-15 km W and SW. Rumbling noises were noted and incandescent block avalanches were generated.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


11 November-17 November 2009

Based on analyses of satellite imagery, the Washington VAAC reported that on 12 November a gas plume from Fuego, possibly containing ash, drifted SSW. On 13 November, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.2-4.7 km (13,800-15,400 ft) a.s.l. and drifted 7 km S. Rumbling noises were noted and incandescence was detected. White fumarolic plumes rose 100 m and drifted S and SW. Small plumes of ash on 16 November were seen on satellite imagery.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


21 October-27 October 2009

Based on analyses of satellite imagery and a pilot observation, the Washington VAAC reported that on 20 October an apparent ash plume from Fuego drifted SSW. On 21 October, multiple ash emissions resulted in an ash cloud that drifted 55 km S. Emissions were also reported the next day. On 26 October, a diffuse gas-and-ash plume drifted W. That same day, INSIVUMEH reported that explosions produced plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l. and drifted 10 km S and SW. Ash fell downwind, rumbling and degassing sounds were reported, and avalanches of blocks descended the flanks. On 27 October, a few ash clouds seen on satellite imagery drifted 90 km NW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


7 October-13 October 2009

On 9, 12, and 13 October, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted W. Some explosions were accompanied by rumbling noises, and avalanches of blocks descended the flanks. On 9 October, a lahar traveled down the Lajas ravine, carrying blocks up to 50 cm in diameter.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 September-15 September 2009

On 10 and 14 September, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted as far away as 10 km W, SW, and S. Some explosions were accompanied by rumbling noises and shock waves. Incandescent material was ejected 100 m high and avalanches descended multiple ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 August-25 August 2009

Based on information from the Tegucigalpa MWO, the Washington VAAC reported that ash was detected within 15 km of Fuego on 19 August. Ash was not identified in satellite imagery. On 21 and 25 August, INSIVUMEH reported that explosions produced plumes that rose to altitudes of 4.2-4.6 km (13,800-15,100 ft) a.s.l. and drifted 5-7 km W and SW. On 21 August rumbling sounds were accompanied by incandescent tephra ejected 75 m high. On 25 August, ashfall was reported in areas to the SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


29 July-4 August 2009

On 31 July and 3 August, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4-4.6 km (13,100-15,100 ft) a.s.l. and drifted W. Some explosions were accompanied by rumbling noises. Incandescent material was ejected 75 m high and avalanches occurred on the main cone. Fumarolic plumes rose 200 m and drifted W and NW. The frequency of explosions significantly increased during 2-3 August.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 July-14 July 2009

On 10 and 14 July, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted 10-15 km W and SW. Some explosions were accompanied by rumbling noises and shock waves. Incandescent material was ejected 75 m high and incandescent avalanches descended several ravines. Fumarolic plumes rose 100 m and drifted S and SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 June-9 June 2009

On 5, 8, and 9 June, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted 10 km W, SW, and S. Some explosions were accompanied by rumbling noises and shock waves detected 12-15 km away. Avalanches descended several ravines. Fumarolic plumes rose 150 m and drifted S and SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 May-26 May 2009

INSIVUMEH reported that on 21 May lahars descended the Santa Teresa and Ceniza ravines to the W and SW of Fuego, respectively, and carried fine material as well as blocks up to 2 m in diameter. During 25-26 May, explosions produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted W, SW, S, and SE. Some rumbling noises were reported. On 25 May, fumarolic plumes rose to an altitude of 4.2 km (13,800 ft) a.s.l. and drifted S and SE. Ashfall was reported in areas to the W and WSW on 26 May.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 April-28 April 2009

On 24 and 28 April, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.8 km (13,500-15,700 ft) a.s.l. and drifted 10 km SW. Some explosions were accompanied by rumbling noises and shock waves detected 5 km away. Avalanches of blocks traveled down the flanks. Fumarolic plumes rose 50-150 m and drifted S, NW, and N. On 28 April, incandescent material was ejected 75-100 m into the air.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 March-31 March 2009

On 27 and 30 March, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.8 km (13,500-15,700 ft) a.s.l. and drifted S and SW. Some explosions were accompanied by rumbling noises, shock waves detected 10 km away, and avalanches of blocks down the W and SW flanks. Fumarolic plumes drifted NE and SW. On 30 March, incandescent material was ejected 75 m into the air. Based on analysis of satellite imagery, the Washington VAAC reported that on 31 March an ash plume drifted E.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


11 March-17 March 2009

On 12, 16, and 17 March, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.2-4.8 km (13,800-15,700 ft) a.s.l. and drifted S and SW. Incandescent material was ejected 75 m into the air. Some explosions produced rumbling sounds heard in nearby towns. White plumes rose 150-200 m above the summit. During 16-17 March, fine ashfall was reported in areas downwind.

Based on analysis of satellite imagery and SIGMET notices, the Washington VAAC reported that during 12-13 March ash plumes drifted S and SW. On 13 March, the ash plume rose to an altitude of 5 km (16,500 ft) a.s.l.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


4 March-10 March 2009

Based on analysis of satellite imagery, the Washington VAAC reported that on 5 March multiple ash plumes from Fuego drifted W. On 6 and 10 March, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.2-4.8 km (13,800-15,700 ft) a.s.l. and drifted 12-15 km S and SW. Some strong explosions were accompanied by rumbling noises, shock waves detected 8 km away, avalanches of blocks down all flanks, and ash plumes that rose to an altitude of 5 km (16,400 ft) a.s.l. Ashfall was reported in areas to the SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


18 February-24 February 2009

Based on analysis of satellite imagery, the Washington VAAC reported that on 18 February ash plumes from Fuego rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted WSW. On 20 and 24 February, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted 6-8 km SW. Some explosions produced rumbling sounds and shock waves. Incandescent material was ejected 150 m above the crater. Incandescent avalanches of blocks traveled down the W and SW flanks.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


4 February-10 February 2009

On 6, 8, and 10 February, INSIVUMEH reported that multiple explosions from Fuego produced ash plumes that rose to altitudes of 4.1-5.4 km (13,500-17,700 ft) a.s.l. and drifted S and SW. Ashfall was reported in areas downwind. Some explosions produced rumbling sounds and constant avalanches of blocks descended the flanks. On 8 February, explosions were accompanied by shock waves that were detected 10-15 km away.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 January-3 February 2009

INSIVUMEH reported that on 30 January and 3 February, multiple explosions from Fuego produced gray plumes that rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted S and SE. Some explosions produced rumbling sounds and shock waves. Fumarolic plumes rose 100 m above the crater. On 30 January, incandescent material was ejected 50-100 m above the crater and avalanches from the crater rim traveled down multiple ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 January-20 January 2009

Based on information from the Central American FIR, the Washington VAAC reported that on 14 January an ash plume from Fuego rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted WSW. On 19 and 20 January, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted 7 km NW, W, and SW. Some explosions produced rumbling sounds. Avalanches occurred on the S and SW flanks.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


7 January-13 January 2009

INSIVUMEH reported that during 8-9 January, multiple explosions (3-5 per hour) from Fuego produced ash plumes that rose to altitudes of 4.3-5.4 km (14,100-17,700 ft) a.s.l. and drifted 10-15 km S and SW. The explosions produced rumbling sounds and shock waves that were detected 10-15 km away. Ashfall was reported in areas downwind. Constant avalanches of blocks descended the S and SW flanks. Based on analysis of satellite imagery and information from the Tegucigalpa MWO, the Washington VAAC reported that on 10 January a diffuse plume drifted W.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


31 December-6 January 2009

Based on analysis of satellite imagery, the Washington VAAC reported that on 1 January two ash plumes from Fuego drifted N. INSIVUMEH reported that during 4-6 January multiple explosions produced ash plumes that rose to altitudes of 4.1-5.1 km (13,500-16,700 ft) a.s.l. and drifted 12 km W and SW. Ashfall was reported in areas downwind. Some explosions produced rumbling sounds and shock waves that were detected 10 km away. Constant avalanches of blocks descended the S and SW flanks.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


10 December-16 December 2008

Based on NOTAM's ("Notices to Airmen"), the Washington VAAC reported that on 9 December a possible gas-and-ash plume from Fuego rose to an altitude of 4.9 km (16,000 ft) a.s.l., drifted N, and dissipated rapidly. INSIVUMEH reported that on 12 December explosions produced ash plumes that rose to altitudes of 4.1-5 km (13,500-16,400 ft) a.s.l. and drifted SSW. The explosions produced rumbling and degassing sounds, and shock waves were detected 10 km away.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


19 November-25 November 2008

INSIVUMEH reported that during 20-21 and 25 November explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.6 km (13,500-15,100 ft) a.s.l. and drifted W and S. The explosions produced rumbling and degassing sounds, and shock waves were detected 10 km away. Lava flowed 150 m W towards the Taniluyá ravine and incandescent material rolled down the flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 September-30 September 2008

Based on information from the Tegucigalpa MWO, the Washington VAAC reported that on 18 September a possible ash plume from Fuego rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SSW. INSIVUMEH reported on 24 September that a lava flow traveled 300 m W towards the Seca ravine. Avalanches were generated from the lava flow front. Explosions generated ash plumes that rose to an altitude of 4.1 km (13,500 ft) a.s.l. and drifted W.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


20 August-26 August 2008

INSIVUMEH reported that on 20 August lahars descended several rivers to the S and SE of Fuego, carrying fine material as well as blocks up to 1 m in diameter. Strong currents in Río Cenizas and El Jute were noted. During 25-26 August, explosions produced ash plumes that rose to an altitude of 4.1 km (13,500 ft) a.s.l. and drifted SW. Fumarolic plumes rose to an altitude of 4 km (13,100 ft) a.s.l. and also drifted SW. A 300-m-long lava flow traveled W towards the Santa Teresa ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 July-5 August 2008

INSIVUMEH reported that a lahar descended El Jute River to the SE of Fuego on 31 July, carrying fine material as well as blocks. A report on 1 August indicated that explosions produced ash plumes that rose to an altitude of 4.1 km (13,500 ft) a.s.l. and drifted W and SW. Rumbling noises and shockwaves occasionally accompanied the explosions.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 July-8 July 2008

INSIVUMEH reported that on 4 July there were rumbling noises from Fuego and the seismic network detected multiple explosions. A lava flow traveled 100 m W towards the Santa Teresa ravine. A lahar carrying blocks descended the Ceniza ravine to the SW. On 7 and 8 July, explosions produced ash plumes that rose to altitudes of 4-4.5 km (13,100-14,800 ft) a.s.l. and drifted S, SE, and SW. Incandescence at the summit was observed and constant avalanches of blocks from lava-flow fronts descended the W flank.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 June-24 June 2008

On 18 June, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to an altitude of 4.3 km (14,100 ft) a.s.l. and drifted W and SW. Incandescent material was ejected 50 m above the crater. Constant avalanches of blocks descended the W flank and rumbling and degassing noises were reported. On 20 June, a lahar that was hot in areas, descended the Ceniza drainage to the SW, dragging tree branches and blocks 0.5-1 m in diameter.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 June-17 June 2008

INSIVUMEH reported that during 13-17 June, explosions from Fuego produced ash plumes that rose to altitudes of 3.9-4.4 km (12,800-14,400 ft) a.s.l. On 13 June, lahars descended the Santa Teresa (W) and Ceniza (SW) drainages and a lava flow traveled 100 m towards the Santa Teresa. On 15 June, rumbling noises were accompanied by shock waves. On 17 June, fumarolic plumes were noted and incandescent material visible at night was ejected about 50 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 May-3 June 2008

During 28-30 May, INSIVUMEH reported explosions from Fuego and ash plumes that rose to altitudes of 4.1-4.4 km (13,500-14,400 ft) a.s.l. and drifted S and SW. The explosions produced rumbling and degassing sounds, and shock waves detected several kilometers away. Avalanches descended W into the Taniluyá and Santa Teresa ravines. On 2 June, incandescent material was ejected 50-100 m above the crater and a small lava flow traveled 100 m W towards the Santa Teresa ravine. On 3 June, cloudy weather inhibited visual observations, but explosions were heard.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 May-27 May 2008

INSIVUMEH reported that explosions from Fuego produced ash plumes to altitudes of 4.1-4.5 km (13,500-14,800 ft) a.s.l. during 22-27 May. The plumes drifted 5 km SW and ashfall was reported in areas downwind. The explosions produced rumbling and degassing sounds, and shock waves that rattled windows and structures 10-15 km away. During 26-27 May, constant avalanches of blocks descended W into the Taniluyá and Santa Teresa ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 April-29 April 2008

The Washington VAAC reported that an ash plume from Fuego was visible on satellite imagery on 23 April and drifted SW. On 28 April, INSIVUMEH reported that explosions (1 per hour) produced ash plumes to an altitude of 4.4 km (14,400 ft) a.s.l. The plumes drifted 5 km SW. The explosions produced noises audible 15 km away and shock waves that rattled windows and structures in nearby villages.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


16 April-22 April 2008

INSIVUMEH reported that explosions (1-2 per hour) from Fuego produced ash plumes to altitudes of 4.3-4.7 km (14,100-15,400 ft) a.s.l. during 15-21 April. The plumes drifted 5-8 km SW and ashfall was reported from areas downwind. The explosions produced rumbling and degassing sounds, and shock waves that rattled windows and structures 5-15 km away. The Washington VAAC reported that multiple ash plumes were visible on satellite imagery during 18-19 April and drifted mainly SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


26 March-1 April 2008

The Washington VAAC reported that multiple ash puffs from Fuego were visible on satellite imagery on 31 March drifting SW and on 1 April.

Source: Washington Volcanic Ash Advisory Center (VAAC)


19 March-25 March 2008

INSIVUMEH reported that during 22-25 March more frequent explosions (4-5 per hour) from Fuego produced ash plumes to altitudes of 4.1-4.6 km (13,500-15,100 ft) a.s.l. The plumes drifted 6-8 km S and SE. Most explosions produced degassing and rumbling noises, and shock waves that vibrated windows and ceilings within a 5-8 km radius.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 February-19 February 2008

INSIVUMEH reported that during 6-19 February explosions from Fuego produced ash plumes that rose to altitudes of 4-4.7 km (13,100-15,400 ft) a.s.l. Fumarolic plumes rose to altitudes of 3.9-4 km (12,800-13,100 ft) a.s.l.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 January-5 February 2008

Based on observations of satellite imagery, the Washington VAAC reported that ash plumes from Fuego rose to an altitude of 5 km (16,500 ft) a.s.l. and drifted W on 4 February.

Source: Washington Volcanic Ash Advisory Center (VAAC)


23 January-29 January 2008

INSIVUMEH reported on 24 January that explosions from Fuego produced ash plumes that rose to altitudes of 4.2-4.5 km (13,800-14,800 ft) a.s.l. ands drifted S, SW, and W. Some explosions produced shock waves that were detected 3 km away. At night, small avalanches of blocks traveled W towards the Taniluyá ravine. Based on reports from INSIVUMEH, CONRED reported on 28 January that the Alert Level was lowered to Green.

Based on observations of satellite imagery, the Washington VAAC reported that a narrow plume of gas and possible ash drifted SW on 30 January.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED); Washington Volcanic Ash Advisory Center (VAAC)


9 January-15 January 2008

INSIVUMEH reported on 11 January that weak explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.3 km (13,500-14,100 ft) a.s.l. CONRED reiterated that the Alert Level remained at Yellow.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


26 December-1 January 2008

Based on observations of satellite imagery, the Washington VAAC reported that a probable ash plume from Fuego drifted N on 26 December.

Source: Washington Volcanic Ash Advisory Center (VAAC)


19 December-25 December 2007

Based on observations of satellite imagery, the Washington VAAC reported that ash plumes from Fuego rose to an altitude of 5.2 km (17,000 ft) a.s.l. drifted SW on 21 December. Gas or ash plumes were seen on satellite imagery on 23 December and drifted W. According to CONRED, INSIVUMEH reported on 24 December that an ash plume drifted SW. CONRED reiterated that the Alert Level remained at Yellow.

Sources: Washington Volcanic Ash Advisory Center (VAAC); Coordinadora Nacional para la Reducción de Desastres (CONRED)


12 December-18 December 2007

INSIVUMEH reported on 12 October that explosions from Fuego produced ash plumes that rose to altitudes of 4.2-4.8 km (13,800-15,700 ft) a.s.l. and drifted W and SW. Ashfall was reported from areas to the W. The explosions were accompanied by rumbling noises, degassing sounds, and shock waves detected up to 15 km away. The Washington VAAC reported a thermal anomaly along with ash plumes drifting W and NW that were visible on satellite imagery during 15-16 December. INSIVUMEH reported that on 17 December, Fuego returned to normal levels after the 15-16 December eruption. A few explosions were registered by the seismic network and ash plumes rose to altitudes of 4.5 km (17,800 ft) a.s.l. plumes drifted S and SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


28 November-4 December 2007

Based on observations of satellite imagery, the Washington VAAC reported that an ash plume from Fuego drifted W on 29 November.

Source: Washington Volcanic Ash Advisory Center (VAAC)


24 October-30 October 2007

Based on observations of satellite imagery, the Washington VAAC reported that multiple ash "puffs" from Fuego drifted SE on 26 October.

Source: Washington Volcanic Ash Advisory Center (VAAC)


10 October-16 October 2007

INSIVUMEH reported on 10 October that explosions from Fuego produced ash plumes that rose to altitudes of 4-5 km (13,000-16,400 ft) a.s.l. and drifted N and NW. Explosions were accompanied by rumbling noises and sounds resembling an aircraft engine. Avalanches due to collapses from the growing cone in the inner crater descended W into the Taniluyá and Santa Teresa ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


29 August-4 September 2007

On 31 August, INSIVUMEH reported that a lahar, 8 m wide and 1.5 m high, descended W down Fuego's Santa Teresa ravine, carrying fine material, tree branches, and blocks. On 3 September, fumarolic plumes rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted W and SW. A 300-m-long lava flow continued to advance W down the Taniluyá River valley. Avalanches in the Ceniza River valley were noted. During 3-4 September, explosions produced ash plumes that rose to an altitude of 4.5 km (14,800 ft) a.s.l. and drifted SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 August-28 August 2007

On 24 August, INSIVUMEH reported that fumarolic plumes from Fuego rose to an altitude of 3.9 km (12,800 ft) a.s.l. and drifted W. A lahar carried tree trunks, branches, and blocks down the Lajas drainage to the SE. A lahar again affected the drainage on 27 August. Explosions on 28 August produced ash plumes that rose to an altitude of 4.1 km (13,500 ft) a.s.l.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 August-21 August 2007

Based on a Guatemala City surface report, the Washington VAAC reported activity at Fuego. A hotspot was visible on satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)


8 August-14 August 2007

INSIVUMEH reported that on 8 August, a Strombolian eruption of Fuego produced gas-and-ash plumes that rose to altitudes of 4.8-5.6 km (15,700-18,400 ft) a.s.l. and drifted W and SW. Lava flows advanced and avalanches of incandescent blocks traveled down river valleys, including the Ceniza river valley to the SW. Several pyroclastic flows descended the flanks and ashfall was reported in villages to the W, SW, and S. CONRED raised the Alert Level to Orange (level 3 on a scale of 1-4) in surrounding communities on 8 August, based on a later report from INSIVUMEH.

On 9 August, there was a substantial decrease in vigor of the Strombolian eruption. Explosions produced plumes to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l. and drifted SW. A lava flow traveled 1.5 km SW down the Ceniza river valley and landslides of incandescent blocks were observed. INSIVUMEH issued a report later that day stating that the activity had further decreased to normal levels. A few explosions produced plumes to an altitude of 4.3 km (14,100 ft) a.s.l. and drifted SW.

On 10 August, CONRED decreased the Alert Level to Yellow. INSIVUMEH reported that the lava flows that were active during 8-9 August were no longer visible. On 10 and 13 August, small explosions produced plumes to an altitude of 4.3 km (14,100 ft) a.s.l. and drifted SW.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


1 August-7 August 2007

INSIVUMEH reported that explosions from Fuego expelled incandescent material 50-75 m above the crater on 1 August. Incandescent avalanches traveled 500-700 m down the S and W flanks. Rumbling noises and shock waves were noted at nearby locations. On 2 August, a moderate eruption produced pyroclastic flows that traveled approximately 2 km SSW down the Ceniza River valley. A resultant ash plume rose to an altitude of 5.3 km (17,400 ft) a.s.l. and produced ashfall in areas to the S, SW, and W for several minutes.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 July-24 July 2007

INSIVUMEH reported that during 17-18 July, gas plumes from Fuego rose to an altitude of 3.9 km (12,800 ft) a.s.l. and drifted SW. On 18 July, a hot lahar, 20 m wide and 1.5 m high, carried blocks 1-1.5 m in diameter to the W down the Santa Teresa ravine. On 20 July, the seismic network recorded 21 explosions. Associated ash plumes rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted W and SW. Rumbling noises were reported.

CONRED raised the Alert Level to Yellow in surrounding communities on 22 July, based on a report from INSIVUMEH. INSIVUMEH reported that Vulcanian explosions produced ash plumes to altitudes of 4.1-5.2 km (13,500-17,100 ft) a.s.l. and expelled incandescent material 75-250 m above the crater. The explosions were accompanied by rumbling noises and shock waves that rattled ceilings and windows within a 25 km radius. Ashfall was reported from areas approximately 7-8 km to the SW, and incandescent avalanches of blocks rolled 500-800 m down the S flanks towards areas of vegetation. A new lava flow that initiated from an area 100 m below the S edge of the central crater traveled about 100 m.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


27 June-3 July 2007

INSIVUMEH reported that on 27 June, a new 100-m-long lava flow from Fuego was observed that somewhat paralleled the previous flow from March/April 2007. The older lava flow on the S flank continued to advance and produce incandescent blocks that rolled W into the Taniluyá River valley. On 29 June, pyroclastic explosions propelled material about 75 m above the crater. Seven explosions produced whitish plumes to an altitude of about 4 km (13,100 ft) a.s.l. and drifted S.

According to CONRED, INSIVUMEH reported on 1 July that during a Strombolian eruption, lava was propelled 200-300 m above the summit. Resulting lava flows traveled about 800 and 1,300 m to the W. Rumbling sounds were heard and shockwaves rattled windows in near by villages. Ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. and drifted W. Multiple pyroclastic flows traveled 1.3-2 km to the W. Based on the report, CONRED raised the Alert Level to Orange in surrounding communities.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


23 May-29 May 2007

On 25 May, CONRED reported that the Alert Level for Fuego was lowered from Yellow to Green based on recent communication with nearby communities and monitoring by scientists at INSIVUMEH. During 28-29 May, INSIVUMEH reported that the lava flow on the S flank continued to advance and produce incandescent blocks that rolled W into the Taniluyá River valley. Low rumbling noises were heard during 26-27 May and occasionally accompanied pyroclastic explosions. Additional explosions produced plumes to an altitude of 4.1 km (13,500 ft) a.s.l. and expelled incandescent material about 100 m above the crater. Avalanches of blocks were observed on the S and SW flank. Gray plumes drifted S. Steam-and-gas plumes rose to an altitude of 4.6 km (15,100 ft) a.s.l.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Coordinadora Nacional para la Reducción de Desastres (CONRED)


18 April-24 April 2007

INSIVUMEH reported that on 20 and 23 April, Strombolian activity was observed at Fuego; incandescent material was ejected about 50-75 m above the summit and blocks descended 300 m down the S and W flanks. On 20 April, sounds resembling locomotives accompanied the eruption, and lava overflowed the crater on the S flank and traveled 100 m. The Washington VAAC reported that an intense hotspot seen on satellite imagery on 21 April was likely caused by a lava flow to the SW, according to information from INSIVUMEH. A plume drifting SW was also visible on satellite imagery and may have been a result of fires started by lava flows; the plume may have also contained light ash and gas. On 23 April, INSIVUMEH reported that pyroclastic flows and incandescent avalanches traveled down SE and SW ravines. Ash explosions caused light ashfall in areas S of the volcano and fumarolic and gas plumes rose to an altitude of 4 km (13,000 ft) a.s.l.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


21 March-27 March 2007

Based on satellite imagery, the Washington VAAC reported that a small plume from Fuego drifted E on 21 March. During 21-22, 24, and 26-27 March, INSIVUMEH reported that explosions produced gas-and-ash plumes that rose to altitudes of 4.7-5.1 km (15,400-16,700 ft) a.s.l. Ashfall was reported from areas 5-8 km SSE and 9 km W. On 24 March, explosions were followed by lava blocks rolling down the W flank toward the Taniluyá River valley and gas emissions. Resultant plumes drifted 15 km SW. Similar activity on 26 March caused ashfall in areas 10-25 km away to the W and SE. On 27 March, the Washington VAAC reported that another small plume was visible on satellite imagery drifting W.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


14 March-20 March 2007

INSIVUMEH reported that incandescent material from Fuego was ejected 200 m above the summit on 15 March. The activity was accompanied by rumbling noises and shockwaves that vibrated windows several kilometers away. Two lava flows were observed; one traveled about 1,500 m W toward the Taniluyá River valley. An ash plume drifted S and SW. On 16 March, Strombolian activity propelled material 300 m above the summit and shockwaves were felt as far as 15 km away. The lava flows from 15 March advanced and three more flows were observed in different ravines on 16 March. Ash plumes rose to an altitude of 5.4 km (17,799 ft) a.s.l. and drifted S, SW, and E. Two pyroclastic flows traveled about 800 m; one NW and another W and SW.

Based on pilot reports, INSIVUMEH reports, and satellite imagery, the Washington VAAC reported that ash plumes reached altitudes of 4.1-6.1 km (13,500-20,000 ft) a.s.l. during 15-16 March. A hotspot was visible on satellite imagery both days.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


7 March-13 March 2007

INSIVUMEH reported on 9 and 13 March that explosions from Fuego produced ash plumes that rose to altitudes of 4-4.2 km (13,000-13,800 ft) a.s.l. and drifted SE. Rumbling noises were heard from surrounding villages. Lava flows extended ~100-150 m W toward the Taniluyá River valley and avalanches occurred from the lava-flow fronts. On 12 March, incandescent material was ejected about 15-20 m above the central crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 January-30 January 2007

Based on a pilot report and information from INSIVUMEH, the Washington VAAC reported that a diffuse plume from Fuego reached an altitude of 4 km (13,000 ft) a.s.l. and drifted NE. A hotspot over the crater was visible on satellite imagery. INSIVUMEH reported that approximately during 21-29 January, incandescent material was propelled up to 100 m above the summit and incandescent blocks rolled about 500 m S and SW down the flanks. During 26 and 29 January, incandescent blocks broke away from lava-flow fronts and rolled S towards the source of the Ceniza River.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


10 January-16 January 2007

INSIVUMEH reported that explosions from Fuego produced white and gray plumes that rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted SW on 12 January. Incandescent material was propelled up to 75 m above the summit and incandescent blocks rolled W towards the Taniluyá and Santa Teresa ravines on 12 January and S towards the Ceniza ravine on 12 and 16 January. Based on information from the Tegucigalpa MWO and satellite imagery, the Washington VAAC reported that a faint plume was seen on 12 January drifting W.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 January-9 January 2007

INSIVUMEH reported that during 4-5 January, constant avalanches of incandescent material from Fuego's central crater and lateral crater (about 70 m from the S edge of the central crater) descended SW towards the Taniluyá River ravine. Several explosions produced shock waves and gas-and-ash clouds that reached altitudes of 4.2-4.8 km (13,800-15,700) a.s.l. Fine ashfall was noted in areas S and about 9-15 km SW of the summit.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 November-21 November 2006

INSIVUMEH reported that on 15 November lava flows from Fuego traveled about 150 m SW and avalanches occurred from the lava-flow fronts. On 17 November, three out of seven explosions propelled incandescent material 100 m above the central crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 September-3 October 2006

INSIVUMEH reports noted that frequent explosions at Fuego during 14-29 September sent incandescent lava 75-100 m above the crater rim and generated hot avalanches SW towards the Taniluyá River.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 August-22 August 2006

Ash explosions from Fuego reached 300-800 m above the summit (13,300-15,000 ft a.s.l.) on 16 and 21 August. Explosions of incandescent material on 16, 18, and 21 August produced avalanches that descended 300-500 m SW towards the Ceniza, Taniluyá, and Santa Teresa river valleys.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 June-4 July 2006

On 29 June, INSIVUMEH reported that pyroclastic flows from Fuego traveled mainly SW along the Ceniza River and a lesser number moved SW along the Taniluyá River. According to a news report, on 29 June an ash plume reached a height of 2.2 km above the summit (19,500 ft a.s.l.) and drifted W. On 3 July, explosions propelled incandescent material hundreds of meters above the central crater (~13,000 ft a.s.l.). Avalanches traveled ~300-500 m SW along the Ceniza River.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Associated Press


24 May-30 May 2006

On 29 May, INSIVUMEH reported that fumarolic emissions from Fuego reached a height of ~125 m above the volcano (~12,750 ft a.s.l.). Lava flows extended ~400 m SW toward the Ceniza River. Avalanches occurred from the lava-flow fronts. Incandescent material was propelled from the crater tens of meters. Plumes reached heights of 200 m above the crater (13,000 ft a.s.l.) and dispersed W and NW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


17 May-23 May 2006

On 17 May, INSIVUMEH reported that fumarolic emissions reached ~600 m above the volcano (14,300 ft a.s.l.). and drifted E and W. Active lava flows reached ~100 m SW toward the Taniluyá River and ~500 m SW toward the Ceniza River. Avalanches occurred from lava-flow fronts. The Washington VAAC reported a short low-level plume on 18 May that drifted N from the volcano.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


12 April-18 April 2006

On 17 April, explosions at Fuego ejected incandescent material ~50-75 m high, and gas plumes to ~150-200 m above the volcano (12,800-13,000 ft a.s.l.). Incandescent landslides traveled down the volcano's S and W flanks. Lava flowed ~400 m S towards Taniluyá ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 March-28 March 2006

During 22-28 March, several explosions at Fuego ejected incandescent material ~50-75 m high and gas plumes to ~300 m above the volcano (13,300 ft a.s.l.). Short pyroclastic avalanches occurred on the upper flanks. On 28 March, lava flowed ~450 m S and avalanches occurred from the lava-flow fronts.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 March-7 March 2006

On 6 and 7 March, small ash emissions from Fuego were visible on satellite imagery and reached a maximum height of 4.6 km (~15,000 ft) a.s.l.

Source: Washington Volcanic Ash Advisory Center (VAAC)


1 February-7 February 2006

During 1-3 February, weak-to-moderate explosions occurred at Fuego. Shock waves from the explosions were sometimes felt in villages near the volcano. Small avalanches of volcanic material traveled down Fuego's S and W flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 January-24 January 2006

Weak to moderate explosions continued at Fuego during 18-24 January 2006, sending dark gray ash plumes as high as 800 m (2,600 feet) above the crater. Explosion noises could be heard 25-30 km away. Incandescent lava ejections rising 100 m above the crater were seen on the night of 22-23 January that resulted in block avalanches down the SW flank.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 January-17 January 2006

During 11-16 January, moderate-to-strong explosions at Fuego produced ash plumes that rose to ~1.5 km above the volcano (or 4,900 ft a.s.l.). Incandescent lava was hurled ~40 m high.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Craig Chesner (Eastern Illinois University, Charleston, Illinois, USA); Sid Halsor, Wilkes Barre University


4 January-10 January 2006

During 4-9 January, moderate-to-strong explosions at Fuego produced ash plumes that rose to ~1 km above the volcano (or 15,600 ft a.s.l.). The explosions were accompanied by rumbling sounds and acoustic waves that shook windows and doors in villages near the volcano. Avalanches of volcanic material traveled down the volcano's SW flank.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 December-3 January 2006

An eruption began at Fuego on 27 December around 0545 and produced lava flows that traveled down Taniluya (SW) and Seca (W) ravines, initially extending ~800 m and 1,200 m, respectively. At 0602 a pyroclastic flow descended Seca Ravine, producing a S-drifting column of ash that rose to a height of ~2 km above the volcano (or 18,900 ft a.s.l.). Ash fell to the S of the volcano in the port of San Jose. Later that day, the lava flows reached lengths of 1.2 and 1.3 km, and pyroclastic flows traveled 1.8 and 2 km down the Taniluya and Seca ravines, respectively. Lava flows also traveled W toward Santa Teresa ravine, and SE towards Jute and Lajas ravines. A small amount of ash fell W and SW of the volcano in the villages of Panimaché (~7 km SSW), Morelia, Santa Sofía, and Los Tarros.

Volcanic activity continued through 28 December, with incandescent lava clots hurled ~75 m high, lava flows traveling down the volcano's flanks, and a dark gas-and-ash plume rising to ~1 km above the volcano (or 15,600 ft a.s.l.). Avalanches of volcanic material spalled from lava-flow fronts. On the 29th, lava only flowed in Santa Teresa ravine, reaching ~600 m. Moderate explosions continued through 3 January, depositing small amounts of ash in Panimaché village. According to a news article, none of the ~250,000 residents from the 78 communities near the volcano were evacuated.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC); Reuters


21 December-27 December 2005

On 27 December an eruption at Fuego produced an ash plume to a height of ~7.6 km (25,000 ft) a.s.l. that extended SSW and SSE of the volcano. The higher level ash (~7.6 km a.s.l.) drifted W to Honduras, while ash below ~6.1 km (20,000 ft) a.s.l. drifted E to the Pacific coast. According to news articles, two lava flows that were both ~2 km long traveled down the volcano's flanks, but posed no threat to inhabited areas. Articles also reported that about 25,000 local residents were put on alert, and emergency teams said that there was no immediate need for evacuations.

Sources: Washington Volcanic Ash Advisory Center (VAAC); Reuters


14 December-20 December 2005

On 13 December, two lava flows from Fuego reached 200-300 m W and SW of the central crater. Small landslides of incandescent blocks spalled off of the lava flows.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


16 November-22 November 2005

During 17-21 November, lava flows from Fuego continued to travel towards the Ceniza (to the S), Taniluyá (to the S), and Santa Teresa (to the W) ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


9 November-15 November 2005

During 11-14 November, three lava flows were emitted from Fuego. On the 14th, two of the lava flows traveled from the S edge of the central crater 150 m toward the Ceniza ravine, and 400 m toward the Taniluyá ravine, and the third traveled 600 m W toward the Santa Teresa ravine. Avalanches of volcanic material spalled from the fronts of the lava flows.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 November-8 November 2005

During 2-7 November, several weak explosions occurred at Fuego, producing ash plumes that rose to low levels. Lava flows traveled down the volcano's S and SW flanks, extending 600 m towards the Taniluya ravine, and 300 m towards the Cenizas ravine. Avalanches of incandescent material occurred from the lava-flow fronts.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


7 September-13 September 2005

A small eruption at Fuego on 17 July during 1715-1945 produced an ash plume that rose 3.5-4 km above the volcano's crater (or 23,800-25,500 ft a.s.l.). The eruption was accompanied by small pyroclastic flows that traveled SW down Santa Teresa and Taniluyá ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 July-19 July 2005

A small eruption at Fuego on 17 July during 1715-1945 produced an ash plume to a height of 3.5-4 km above the volcano's crater (23,800-25,500 ft a.s.l.). The eruption was accompanied by small pyroclastic flows that traveled down Santa Teresa and Taniluyá ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


6 July-12 July 2005

During 6-11 July, several explosions at Fuego produced low-level plumes. Small avalanches of volcanic material traveled down the S and W sides of the central crater, and from the front of a lava flow.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 June-28 June 2005

From 22-24 June, small incandescent lava expulsions reached ~50 m high and columns of grayish smoke rose ~300 m above the vent (13,300 ft a.s.l.) and drifted W. Weak rumbling and short avalanches of incandescent material accompanied these expulsions. On 27 June a lava flow was observed on the South flank extending approximately 300 m.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 June-7 June 2005

During 1-6 June, several explosions at Fuego produced low-level plumes. Small avalanches of volcanic material occurred on the S and W sides of the central crater. A lava flow, which began on 18 May on the volcano's W flank, extended ~1 km down the volcano's flank. On 2 June, a new lava flow was emitted that traveled ~120 m down Fuego's S flank.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 May-24 May 2005

During 17-20 May, lava flows continued to travel down Fuego's flanks, extending ~400 m W and ~500 m SW of the summit. Short avalanches originated from the lava-flow fronts. Also, explosions sent ash and incandescent volcanic material to low altitudes.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 May-17 May 2005

Small white plumes to ~200 m height were again observed during 11-17 May. Lava flows down the Santa Teresa and Taniluya ravines reached 700 and 500 m long, respectively, with avalanches originating from their fronts.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


4 May-10 May 2005

A lava flow on 9 May extended ~100 m towards the S flank during almost 4 hours of emission. Small plumes 200-300 m high that same day were associated with 29 episodes of weak rumbling noises.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 April-26 April 2005

During 21-25 April, explosions at Fuego generated small lava avalanches to the W and SW. Also, lava flows traveled ~400 m W and ~250 m SW. Blocks of lava spalled from the front of the lava flows.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 March-8 March 2005

During 2-8 March, several explosions at Fuego produced plumes to a maximum height of 1 km above the volcano. Some explosions were accompanied by avalanches of volcanic material that traveled towards the Taniluyá (to the SW) and Santa Teresa ravines. Around 4 March, a lava flow traveled ~200 m down Fuego's SW flank. Blocks of lava spalled from the front of the lava flow.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 January-25 January 2005

During 24-25 January, several weak-to-moderate explosions at Fuego produced ash plumes to a maximum height of 1.5 km above the volcano. The eruptions were accompanied by avalanches of incandescent volcanic blocks towards several ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 December-28 December 2004

On 22 December a narrow lava flow on Fuego's S flank reached a distance of ~200 m from the central crater. Many small block-lava avalanches traveled SW towards the Taniluyá River. The Washington VAAC reported that steam-and-ash emissions on 23 December rose to ~4.5 km a.s.l.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


15 December-21 December 2004

During 15-21 December, several small incandescent avalanches of volcanic material at Fuego traveled mainly SW toward the Taniluyá ravine. Around 20 December a narrow lava flow began to be emitted from the S edge of the volcano's central crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 December-14 December 2004

Several small explosions occurred at Fuego during 8-14 December, producing plumes that rose to ~600 m above the volcano. During the report period, small avalanches of volcanic blocks traveled towards Taniluyá, Ceniza, and Santa Teresa ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 December-7 December 2004

There were several small explosions at Fuego during 1-7 December. During the report period, small avalanches of volcanic blocks traveled in the direction of Taniluyá and Santa Teresa ravines. On the evening of 2 December, a thin lava flow traveled about 100 m SSW of the central crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 November-30 November 2004

During 24-26 November there were several explosions at Fuego. On 25 and 26 November ash plumes from these explosions rose to low levels above the volcano. Incandescent lava was hurled ~100 m above the volcano and avalanches of block lava traveled towards the Taniluyá and Ceniza ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


17 November-23 November 2004

During the report period, avalanches of incandescent volcanic material continued towards the Lajas and Taniluyá ravines on the volcano's SE and SW flanks. Small and moderate explosions expelled abundant incandescent lava to heights ~150 m above the crater. Some explosions generated rumblings, shock waves, and fine ash that was deposited on the skirts of the volcano. Near the end of the report period, the energy level of the eruption lowered, especially the flow of lava towards the Lajas ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


10 November-16 November 2004

During 10-15 November, avalanches of incandescent volcanic material continued towards the major ravines on the volcano's flanks. Avalanches occurred from the fronts of the lava flows. Sounds like that of a locomotive or airplane turbine were heard emanating from the active crater. Small explosions expelled incandescent lava to heights of 75-100 m above the crater. Steam plumes from fumarolic activity reach heights of ~500-600 m above the crater, extending ~4-7 km to the S and SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 November-9 November 2004

During 3-5 November, avalanches of incandescent volcanic material traveled 600-800 m towards the Taniluyá and Ceniza ravines on the volcano's flanks. The avalanches originated from two areas about 20 m below the S edge of Fuego's crater. A few explosions produced low-level plumes. During an eruptive pulse beginning around 0026 on 7 November two lava flows were emitted. Avalanches occurred from the fronts of the lava flows. A ~30-m-high scoria cone was formed in the SW part of the central crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


27 October-2 November 2004

During 28-29 October, several weak explosions at Fuego sent plumes to a maximum height of 300 m above the volcano and volcanic bombs were sometimes thrown ~75 m above the volcano's crater. In addition, avalanches of incandescent volcanic material traveled ~600 m towards the ravine of the Ceniza River.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


20 October-26 October 2004

During 21-22 October, several weak explosions at Fuego sent plumes to a maximum height of ~300 m above the volcano. In addition, avalanches of incandescent volcanic material traveled towards the ravines of Taniluyá and Ceniza on the volcano's flanks. The avalanches originated from two areas about 20 m below the S edge of Fuego's crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 October-19 October 2004

During 14-18 October, several weak explosions at Fuego sent plumes to a maximum height of 800 m above the volcano and volcanic bombs were sometimes thrown 75-100 m above the volcano's crater. In addition, avalanches of incandescent volcanic material traveled towards the ravines of Taniluyá, Ceniza, and Trinidad on the volcano's flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


6 October-12 October 2004

During the evening of 9 October, a narrow lava flow traveled ~800 m down Fuego's SSW flank towards the head of the Taniluyá River. A small sustained lava fountain reached ~75 m above the volcano during the evening of 10 October. On 12 October, a narrow lava flow traveled ~400 m from an area about 20 m below the S edge of the crater. Small avalanches occurred from the lava-flow fronts. Six explosions produced plumes to ~600 m above the volcano's summit. A small lahar traveled towards the Zanjón Barranca Seca Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


29 September-5 October 2004

During 30 September to 4 October several explosions occurred at Fuego, producing ash plumes to a maximum height of 2 km above the volcano. On 30 September, lava avalanches traveled towards Santa Teresa and Taniluya ravines. On 1 October, incandescent lava bombs were hurled ~100 m above the volcano.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


22 September-28 September 2004

Weak explosions at Fuego on 21 September produced white plumes to ~200 m above the volcano. During 25-26 September, several moderate explosions emitted incandescent lava bombs to heights of ~150 m and plumes to 600-900 m above the volcano. The explosions were accompanied by avalanches of volcanic material that traveled W to the head of Santa Teresa Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 September-21 September 2004

Ten explosions on 16 September sent ash columns ~400-600 m high; three ejected incandescent lava and caused block avalanches. White fumarolic plumes typically rose 300-500 m. Similar activity was observed through the 20th. Overnight on 19-20 September weak incandescence was seen from the crater. The highest plume during this period rose ~900 m.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 September-14 September 2004

During 8-13 September, small explosions at Fuego produced low-level plumes and avalanches of volcanic blocks traveled down the volcano's flanks. On 12 September a small lahar occurred down the volcano's flank.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


1 September-7 September 2004

During 2-3 September, small explosions at Fuego produced low-level plumes and avalanches of volcanic blocks traveled down the volcano's flanks. On 4 September a small lahar flowed down the volcano's S flank, partially blocking a road.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 August-31 August 2004

During 30 August to 1 September, several small explosions at Fuego produced plumes to low levels.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


18 August-24 August 2004

During 18-23 August, many weak-to-moderate explosions occurred at Fuego. The explosions expelled lava blocks to ~100 m above the crater and plumes rose to a maximum height of 0.5 km above the crater. Avalanches of incandescent volcanic material traveled to the mouths of several ravines on the volcano's flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


11 August-17 August 2004

During 11-16 August, dozens of weak-to-moderate explosions occurred at Fuego. The explosions expelled lava blocks to ~75 m above the crater and plumes rose to a maximum height of 1.2 km above the crater. Avalanches of incandescent volcanic material traveled to the mouths of several ravines on the volcano's flanks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 July-27 July 2004

A series of strong explosions at Fuego on 21 July during 0630-0950 produced ash plumes to a height of ~2 km above the volcano. Plumes traveled W, SW, and S, depositing ash in several villages near the volcano. Small incandescent avalanches of volcanic material traveled to the mouths of several ravines. Ash emissions and avalanches continued through 27 July.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 July-20 July 2004

During 14-19 July, explosions at Fuego produced plumes to a maximum height of ~1.5 km a.s.l. and avalanches of volcanic material traveled down several ravines flanking the volcano.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


7 July-13 July 2004

On 7 July, an explosion from Fuego generated an avalanche of lava fragments near the headwaters of Santa Teresa ravine. Forty-three weak to moderate explosions were observed during 10-11 July; the explosions produced ashy plumes less than 2 km above the ground that were blown west-southwest at least 20 km from the volcano.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


30 June-6 July 2004

During 1-6 July, small explosions at Fuego produced plumes to ~1.4 km above the volcano that predominately drifted SW. Occasional avalanches of volcanic material traveled down ravines flanking the volcano.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


23 June-29 June 2004

On 28 and 29 June, small explosions at Fuego produced plumes to ~0.8 km above the volcano that predominately drifted SW. Incandescence was visible in the crater at night.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


2 June-8 June 2004

On 1 June, five moderately strong explosions occurred at Fuego with gas-and-ash plumes rising up to 2 km above the summit. Incandescent avalanches of material from these explosions occurred in the Santa Teresa and Río Taniluyá ravines. This pulse of activity was preceded by half an hour and followed by two hours of explosions producing steam plumes rising up to ~0.5 km above the summit. On 6 June, frequent small explosions produced gas plumes that rose to ~0.5 km above the summit and less frequent explosions produced gas-and-ash plumes that rose to ~1.0 km above the summit. Incandescent avalanches from these explosions occurred in the Santa Teresa and Ceniza ravines. A hot lahar, followed 45 minutes later by a smaller lahar, occurred in the Zanjón Barranca Seca ravine on 6 June. Moderate explosions continued on 7 June, producing small gas-and-ash plumes to ~0.5 km above the summit.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


26 May-1 June 2004

During 31 May to 1 June moderate volcanic and seismic activity continued at Fuego, with several explosions producing ash plumes. The highest rising plume reached ~1.5 km above the volcano on 31 May. This explosion also produced avalanches of volcanic material down the ravines of Taniluyá and Santa Teresa.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 May-25 May 2004

During 18-21 May, moderate volcanic activity continued at Fuego. Several explosions produced ash plumes, with the highest one reaching ~1.2 km above the volcano on 20 May. On 21 May, avalanches of incandescent volcanic material traveled toward the ravines of Seca (to the W) and Taniluya (to the SW).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


12 May-18 May 2004

During 10-17 May, moderate volcanic activity continued at Fuego. Several explosions produced ash plumes, with the highest one reaching ~1.8 km above the volcano on 13 May. Explosions on 13 May at 0411 and 0618 emitted incandescent volcanic material ~150 m. In addition, a lahar traveled W toward Seca Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


5 May-11 May 2004

During 5-7 May, explosions at Fuego produced gas-and-ash clouds. On 5 May a small lahar travel W down Seca Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


28 April-4 May 2004

During 28 April to 4 May, explosions at Fuego produced gas-and-ash clouds. On 28 April, an explosion produced an ash plume to ~1.5 km above the volcano, and ash was deposited ~4 km SW of the volcano in the villages of Panimaché I and Panimaché II. In addition, a small avalanche of volcanic material traveled W toward Santa Teresa Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 April-27 April 2004

During 22-27 April, weak explosions at Fuego produced gas-and-steam clouds to ~1 km above the volcano. In addition, small avalanches of volcanic material occasionally traveled W toward Santa Teresa Ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


14 April-20 April 2004

On 16 April, a 5.5-km-wide gas-and-ash plume from Fuego rose to ~6 km a.s.l. and was dispersed to the S. During 18-19 April, small eruptions hurled incandescent material up to 50 m above the vent.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


7 April-13 April 2004

On 12 April weak-to-moderate explosions at Fuego produced plumes to 0.3-1 km above the volcano. Lava flowed 75-100 m from the central crater and avalanches of volcanic material traveled as far as 400 m towards Santa Teresa and Taniluyá ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


31 March-6 April 2004

During 31 March to 6 April, weak-to-moderate explosions continued at Fuego. The highest rising ash plume produced from the explosions reached ~1.2 km above the volcano on 5 April and drifted SSE. Lahars flowed down Seca Ravine on 30 March, and near the village of Sangre de Cristo on 3 April. During the report period, incandescent avalanches of volcanic material traveled down several ravines, including Santa Teresa, Ceniza, and Taniluyá.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 March-30 March 2004

During 24-30 March, sporadic weak explosions and three strong explosions were recorded at Fuego. On 26 March a strong explosion produced an ash plume that reached ~1 km above the vent and caused incandescent avalanches in the Zanjón Barranca Seca and Trinidad ravines. On 29 March two explosions within 7 minutes produced gas-and-ash plumes that reached heights of ~1 km above the vent. A lahar occurred on 29 March in the Zanjón Barranca Seca ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


17 March-23 March 2004

During 16-23 March moderate-to-strong explosions continued at Fuego, producing ash plumes to a maximum height of 1.3 km above the volcano. On 16 March ash fell in the village of Morelia. Explosions during 17-19 March produced incandescent avalanches of volcanic material that traveled down the Seca Ravine. During the report period, ash fell in the village of Sangre de Cristo.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


10 March-16 March 2004

During 9-15 March, moderate-to-strong explosions continued at Fuego, producing ash plumes to a maximum height of 1.7 km above the volcano. Incandescent avalanches of volcanic material traveled as far as 600 m down ravines on the volcano's W, SW, and S flanks and ash fell in villages from Sangre de Cristo to Panimaché.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 March-9 March 2004

During 4-8 March, moderate-to-strong explosions at Fuego produced plumes to ~1.5 km above the volcano. On 5, 7, and 8 March avalanches of incandescent volcanic material traveled as far as 1.5 km down several ravines, including Seca, Taniluyá, Ceniza, and Trinidad. Explosions on the 7th and 8th deposited ash 6-10 km from the volcano, including in the villages of Sangre de Cristo and Panimaché.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 February-2 March 2004

During 25 February to 2 March weak-to-moderate explosions continued at Fuego, producing plumes to ~1.7 km above the crater. Avalanches of volcanic material traveled down several ravines, including Trinidad, Ceniza, Santa Teresa, and Taniluyá (to the W). Explosions on 28 February deposited small amounts of fine ash in the village of Sangre de Cristo, and explosions on 29 February deposited ash W and SW of the volcano in the villages of Yepocapa and La Cruz.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


18 February-24 February 2004

During 18-19 February, several moderate-to-strong explosions at Fuego produced ash plumes to 0.8-1.5 km above the crater. The explosions also produced landslides of incandescent volcanic material that traveled down several ravines: Seca (to the SW), Taniluyá (to the W), Trinidad, Ceniza, and sometimes towards Las Lajas-El Jute. Small amounts of fine ash were deposited to the W in the village of Sangre de Cristo. On 22 and 23 February explosions continued, sending plumes to 1.8 km above the crater. Ash fell in the communities of La Rochela, Ceilán, El Zapote, and Guadalupe.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Siglo XXI News; Prensa Libre


11 February-17 February 2004

INSIVUMEH reported that during 11-16 February several moderate-to-strong explosions occurred at Fuego, producing gas-and-ash plumes to 1.6 km above the crater. Incandescent avalanches traveled a maximum distance of 1 km down several ravines, including Trinidad and Taniluyá to the SW, Seca to the W, Ceniza, and Lajas. During 11-12 February, ash fell in the villages of Panimaché and Sangre de Cristo. According to the Washington VAAC, on 14 February ash was visible on satellite imagery at a height of ~3.5 km above the volcano.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


4 February-10 February 2004

Explosions at Fuego on 8 February produced incandescent avalanches that traveled toward the Seca (to the W), Trinidad, and Taniluyá (to the SW) ravines. Several moderate-to-strong explosions on 9 February produced ash-and-gas plumes that rose to heights of 800-1,500 m above the volcano and drifted W and S. Ash fell as far as 15 km from the volcano, including in the town of Sangre de Cristo and in several ranches (locally termed fincas) in the area. According to the Washington VAAC, on 9 and 10 February small ash plumes were visible on satellite imagery.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


28 January-3 February 2004

During 28 January to 2 February, small-to-moderate explosions occurred at Fuego. The highest rising ash plume was produced from an explosion on 29 January. The plume reached ~1.1 km above the crater and was accompanied by avalanches of volcanic material down Barranca Seca. A small amount of ash fell in Panimaché village and possibly in Santa Sofía. On 31 January two small collapses in the S edge of the central crater produced small avalanches of lava blocks.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


21 January-27 January 2004

On the evening of 22 January two strong explosions at Fuego sent incandescent avalanches a maximum distance of 1 km toward Zanjón Barranca Seca, La Trinidad, and Río Ceniza ravines. The resultant plume rose ~1.5 km above the crater and drifted SSW. No ash fell in populated regions. During the rest of 21-27 January, weak-to-moderate explosions occurred, sending plumes to ~700 m above the crater.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


7 January-13 January 2004

An ash emission from Fuego on 8 January around 1500 rose to ~3 km above the volcano. According to news reports, 25-30 explosions occurred per minute and were accompanied by loud rumbling noises. No evacuations were ordered. Plumes and a relatively strong hotspot were visible on satellite imagery.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC); Prensa Libre; Associated Press


31 December-6 January 2004

During 1-5 January, lava emitted from Fuego flowed 70-100 m from the crater. Avalanches from the lava-flow fronts traveled W toward Santa Teresa ravine and toward Trinidad ravine. Seismic stations on the volcano recorded almost continuous harmonic tremor with moderate frequency and amplitude.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


24 December-30 December 2003

On 30 December, small-to-moderate explosions produced plumes containing little ash that rose to low levels above Fuego. Ash from the explosions was deposited around the volcano's edifice. Small avalanches of volcanic material traveled W toward Santa Teresa ravine and toward Trinidad ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


17 December-23 December 2003

During 18-22 December, moderate explosions at Fuego produced low-level ash plumes that drifted SE and W. Avalanches of volcanic material traveled down the volcano's W and SW flanks toward Taniluya and Santa Teresa ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


10 December-16 December 2003

During 10-16 December, weak explosions at Fuego continued to produce ash clouds that rose 200-1,000 m above the volcano. Explosions and avalanches on 16 December sent volcanic material W and SW towards Taniluya and Santa Teresa ravines. Civil Aeronautics recommended that airplanes avoid the area near the volcano due to ash in the atmosphere.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


3 December-9 December 2003

During 7-9 December, moderate to strong explosions at Fuego expelled ash up to 0.5 km above the crater. The ash was distributed to the N. Incandescent avalanches were observed in the Santa Teresa and Taniluyá ravines.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


26 November-2 December 2003

During 28 November to 1 December, moderate-to-weak explosions at Fuego produced gas-and-ash plumes to heights of 700-900 m above the volcano. The explosions were accompanied by avalanches of volcanic material that traveled towards Teresa, Taniluyá, and Trinidad ravines. On the evening of 1 December, incandescence was seen in the ravines and in the active central crater. During the report period, continuous harmonic tremor was recorded.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


19 November-25 November 2003

Small explosive eruptions at Fuego produced gas-and-ash plumes up to 1.2 km above the crater. During the night of 18-19 November moderate-sized avalanches were observed in the upper Santa Teresa and Trinidad ravines. Night-time incandescence at the summit was common during the week. Periods of harmonic tremor, lasting between 0.5-3 hours, were recorded on 23 November, and almost continuous harmonic tremor was recorded for a period of 21 hours on 24 November.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


5 November-11 November 2003

On the night of 4 November observers saw crater glow and incandescent avalanches. Some incandescent avalanches descended into local valleys. Earlier that day moderate exposions prevailed, throwing material 150 m above the crater's rim. The explosions generated shock waves audible at distance.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


15 October-21 October 2003

A 33-minute-long explosive eruption began at Fuego on 17 October at 0007, producing a gas-and-ash plume to ~1.5 km above the crater. This eruption was preceded and followed by small explosions and seismicity. During one of these earthquakes a small incandescent avalanche descended the Santa Teresa ravine.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


8 October-14 October 2003

On 9 October a pilot saw ash emitted from Fuego that reached a height of ~4.6 a.s.l. No ash was visible on satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)


24 September-30 September 2003

Ash plumes emitted from Fuego were visible on satellite imagery on 28 September. The first emission occurred around 0500 and produced an ash plume that covered an area of 5 x 5 km and drifted S. It was no longer visible by 0800. A second ash emission between 0815 and 0832 rose to ~ 6 km a.s.l. Ash was no longer visible on satellite imagery by 1445.

Source: Washington Volcanic Ash Advisory Center (VAAC)


9 July-15 July 2003

INSIVUMEH reported to the Washington VAAC that on 9 July at 0530 Fuego's lava dome collapsed, producing pyroclastic flows. After the collapse, strong explosions sent ash to ~2 km above the volcano's summit. Ash clouds drifted W and ash fell in communities W and SE of the summit. An ash cloud was visible on satellite imagery.

Sources: Washington Volcanic Ash Advisory Center (VAAC); Prensa Libre


2 July-8 July 2003

INSIVUMEH reported that the eruption at Fuego on 29 June during 1745-2200 consisted mainly of lava flows and avalanches of volcanic material traveling down the volcano's E flank. Incandescence was visible from the city of Antigua and the S coast. Ash fell in villages W and SE of the volcano, including San Pedro Yepocapa. Explosions and tremor were recorded by a seismic station. After the eruption, weak-to-moderate explosions at Fuego produced ash clouds to ~900 m above the volcano and seismographs mainly recorded tremor. Pyroclastic-flow material extended ~1.5 km down the volcano's W flank. Fuego was at Alert Level Yellow and pilots were advised to avoid flying near the volcano.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


25 June-1 July 2003

Based on information from INSIVUMEH, the Washington VAAC reported that a moderate eruption began at Fuego on 29 June at 1700. Lava flows were seen, and ash fell S and SW of the volcano. As of 30 June lava flows were still visible, an ash plume was W of the summit, and seismicity was at low levels. Both days a hot spot was visible on satellite imagery, but an ash cloud could not be distinguished from abundant meteorological clouds in the area.

Source: Washington Volcanic Ash Advisory Center (VAAC)


30 April-6 May 2003

At the end of April U.S. Air Force meteorologists used GOES-12 imagery to describe a thin plume of Fuego's ash that rose to ~7 km a.s.l. and blew SW at 20-30 km/hour. The ash plume was visible for over an hour. On 2 May the Washington VAAC reported that Fuego discharged small eruptions, with most ash remaining near the summit and little if any ash clearly visible on satellite imagery.

Sources: US Air Force Weather Agency; Washington Volcanic Ash Advisory Center (VAAC)


23 April-29 April 2003

The Washington VAAC reported that on 28 April Fuego produced intermittent ash eruptions. One cloud was observed at ~ 7 km a.s.l., traveling SW at 19-29 km per hour. Although remote sensing was complicated by poor visibility due to high cirrus clouds and smoke from fires, some eruptive puffs remained recognizable when they blew over the coast.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


15 January-21 January 2003

INSIVUMEH reported that as of 19 January moderate eruptions continued at Fuego that produced ash clouds to 2 km above the summit. Ash drifted to the S and SW, depositing fine ash in the areas of Rocela, Panimache, and Palo Verde. In addition, incandescent avalanches traveled down canyons on the volcano's flanks.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC)


8 January-14 January 2003

The Washington VAAC reported that an eruption began at Fuego on 8 January around 0500. According to INSIVUMEH, as of 1100 that day the eruption continued with ash explosions and lava flow emission. A steam-and-ash column rose 5.7 km a.s.l. and drifted to the W. In addition, two small-to-moderate pyroclastic flows traveled down the drainage of the Santa Teresa River Valley. CONRED stated that the Alert Level was raised to Orange and several people were evacuated from the town of Sangre de Cristo. According to a news report volcanism decreased the following day, so the Alert Level was lowered from Orange to Yellow.

Sources: Coordinadora Nacional para la Reducción de Desastres (CONRED); Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH); Washington Volcanic Ash Advisory Center (VAAC); EFE News Service; Prensa Libre


24 December-30 December 2002

An explosive eruption and partial crater collapse occurred at Fuego on 26 December around 0905. An ash cloud was generated that reached ~2 km above the volcano and drifted W toward the Yepocapa region. Neither damage nor injuries were reported.

Sources: EFE News Service; Prensa Libre; Siglo XXI News


14 August-20 August 2002

A new cycle of eruptive activity began at Fuego on 16 July that consisted of an increase in Strombolian explosions and the occurrence of high-frequency volcanic tremor for 24 hours. On 28 July a thick gray ash cloud extended 10-15 km in length and drifted to the W. Ash was deposited in the areas of Rochela, Panimaché, Morelia, Santa Sofía, Yepocàpa, and Chimaltenango. This activity was associated with the collapse of the front of a lava flow, which began on 23 January. On 29 July an increase in seismic activity was recorded, the energy of explosions in the crater increased, and there was a 2- to 3-km-long lava flow. On 2 August explosions changed from Strombolian to Vulcanian, ash columns rose 800-1,400 m above the crater, and avalanches of volcanic blocks traveled down the volcano's flanks. The same day, gas emission from the crater decreased significantly, and the SE lava flow did not travel as quickly as it had previously.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)


13 February-19 February 2002

Volcanism increased at Fuego on 12 February, with a ~2-km-long lava flow streaming down its flank towards an unpopulated area. Several shelters have been set up in case lava flows travel towards populated areas or volcanism increases. The volcano remained at Alert Level Yellow.

Source: UN Office for the Coordination of Humanitarian Affairs (OCHA)


30 January-5 February 2002

Based on information from INSIVUMEH, the Washington VAAC reported that on 1 February at 0930 ash, steam, and lava were emitted from Fuego. An ash-and-steam cloud rose to ~4.5 km a.s.l. and drifted to the SW. No ash was seen on satellite imagery, but a hotspot was visible on infrared imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)


23 January-29 January 2002

Observations in late January revealed that Fuego was erupting a lava flow down its E flank. The flow stretched several hundred meters below the summit before falling apart on steep slopes. The toe of the flow calved off about once a minute, but the volume of material was not sufficient to generate pyroclastic flows. No explosive activity was observed and only low-level tremor was recorded. Coordinadora Nacional para la Reducción de Desastres (CONRED) and INSIVUMEH are monitoring the situation at the volcano.

Source: US Geological Survey


9 January-15 January 2002

An eruption began at Fuego on 4 January during 0200-0300. A probable explosion was followed by Strombolian-type ejections and continuous tremor. No lava flows were visible. Until at least 9 January intermittent mild-to-moderate explosions produced ash clouds that rose 400-600 m above the cone.

Source: US Geological Survey


6 December-12 December 2000

The Washington VAAC reported that a small eruption at approximately 1645 on 9 December sent ash to ~ 4 km a.s.l. (near-summit level). The small ash cloud drifted to the W and NW, was initially dense, and rapidly dissipated so that it was no longer visible on satellite imagery by 2345. Throughout the day, occasional strong hot spots were visible on GOES-8 multi-spectral imagery. According to the Washington VAAC, on the evening of 9 December a volcanologist with INSIVUMEH in Guatemala stated that Fuego had shown increased instability with several explosions. The last reported eruption of Fuego sent ash to ~4 km a.s.l on 29 August 2000.

Source: Washington Volcanic Ash Advisory Center (VAAC)


Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

09/1971 (CSLP 85-71) Strong eruption during 14-15 September causes ashfall and pyroclastic flows

03/1973 (CSLP 24-73) Fine ash from February-March eruption falls in a 70-km radius

10/1974 (CSLP 134-74) Strong eruptions and heavy ashfall

12/1974 (CSLP 171-74) Unusual sky observations from many locations; pilots observe dust layer

01/1975 (CSLP 171-74) Optical effects at sunset indicate volcanic dust in the atmosphere

08/1975 (CSLP 134-74) Sporadic explosions and ashfall through 4 August

10/1975 (NSEB 01:01) Occasional ash emissions in September and October

03/1977 (NSEB 02:03) Steam plume from a S-flank vent

04/1977 (NSEB 02:04) Small ash eruption on 19 April

09/1977 (NSEB 02:09) Ash emission almost continuous during 12-13 September

10/1977 (NSEB 02:10) Steam and ash emission continues intermittently through late October

11/1977 (NSEB 02:11) Increased activity continues through mid-November

12/1977 (NSEB 02:12) Intermittent black ash emissions and glow

01/1978 (SEAN 03:01) Largest eruption since 1974

02/1978 (SEAN 03:02) Two new lava flows, the first since 1966

03/1978 (SEAN 03:03) Ash emission continues

04/1978 (SEAN 03:04) Mild to moderate ash emission continues

05/1978 (SEAN 03:05) Mild to moderate ash eruptions continue

06/1978 (SEAN 03:06) Two new lava flows and a large ash cloud

07/1978 (SEAN 03:07) Lava flows, hot avalanches, and explosions in June; activity declines in July

08/1978 (SEAN 03:08) More ash emission and hot avalanches; no new lava flows

09/1978 (SEAN 03:09) 5,500-m ash cloud and hot avalanches; probable dome visible above crater rim

10/1978 (SEAN 03:10) Summit dome growing, but explosive activity declines

11/1978 (SEAN 03:11) Avalanches from new block lava flow; brief moderate Vulcanian activity

12/1978 (SEAN 03:12) Lava flow stops, but intermittent fountaining and ash emission persist

01/1979 (SEAN 04:01) New lava flow and block avalanches

02/1979 (SEAN 04:02) More block lava down the E flank

03/1979 (SEAN 04:03) Summit fissure forms and block lava extrusion resumes

04/1979 (SEAN 04:04) Frequent ash emission and more block lava

05/1979 (SEAN 04:05) Ash emission weaker; no new lava flows

06/1979 (SEAN 04:06) Brief strong incandescent tephra emission

07/1979 (SEAN 04:07) Intermittent tephra emission, some incandescent

08/1979 (SEAN 04:08) Activity declines to weak fumarolic emission

09/1979 (SEAN 04:09) Activity limited to steaming but heavy rains produce destructive mudflows

10/1979 (SEAN 04:10) New crater high on S flank

02/1980 (SEAN 05:02) Fumarolic activity continues; summit area described

03/1981 (SEAN 06:03) Gas emission; no significant changes in the summit area

01/1987 (SEAN 12:01) Incandescent tephra

05/1987 (SEAN 12:05) Earthquake swarm; deformation; vapor plume

07/1987 (SEAN 12:07) Small plume; possible microearthquake swarm

08/1987 (SEAN 12:08) Gas emission and microearthquakes

01/1988 (SEAN 13:01) Gas plumes with some ash

01/1990 (BGVN 15:01) Strong gas plume extends several tens of kilometers from the summit crater

03/1990 (BGVN 15:03) Continuous gas emission; summit morphology appears unchanged since 1980

02/1991 (BGVN 16:02) Prominent plume; moderate SO2 emission

05/1992 (BGVN 17:05) Seismicity and continued fumarolic activity

12/1996 (BGVN 21:12) A white-to-gray smoke column seen rising over the crater

04/1999 (BGVN 24:04) Eruption on 21 May dropped up to 40 cm of ash on local population; small lava flow

07/1999 (BGVN 24:07) Moderate Strombolian eruptions 21 May-1 September

12/1999 (BGVN 24:12) 28-29 December explosions expelled ash and a 900-m-tall plume

01/2000 (BGVN 25:01) Satellite data reveals hot spot; field observers see January-February ash puffs

08/2001 (BGVN 26:08) Seismic activity during April and December, eruption in September 2000

03/2002 (BGVN 27:03) Costly 1999 aircraft-ash encounters due to ash plumes

08/2002 (BGVN 27:08) Explosions, ash emission, and lava flows during January-February and July 2002

01/2003 (BGVN 28:01) Explosive eruptions from September 2002 through January 2003

10/2003 (BGVN 28:10) Explosive eruptions and lava flows through October

11/2004 (BGVN 29:11) Explosions and lava flows continued in November-December 2003

08/2005 (BGVN 30:08) Ongoing ash emissions, lava flows, and associated hazards into 2005

11/2007 (BGVN 32:11) Variable explosive activity continues sporadically, July 2005-December 2006

12/2007 (BGVN 32:12) Moderate Strombolian eruptions, including pyroclastic flows, continue into early 2008

12/2009 (BGVN 34:12) Many small ash plumes and some lava flows during 2008-2009; instrumented study

06/2011 (BGVN 36:06) Frequent plumes and avalanches; occasional incandescence and lahars

05/2013 (BGVN 38:05) Continuous activity and a VEI 3 eruption during 13-14 September 2012

04/2014 (BGVN 39:04) Explosions, ash plumes, lava flows, and lahars during April 2013-June 2014




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


09/1971 (CSLP 85-71) Strong eruption during 14-15 September causes ashfall and pyroclastic flows

Card 1290 (17 September 1971) Sudden violent ash eruption on 14 September

R. Stoiber telephoned the following report on 17 September. "A sudden, violent ash eruption and possible lava flow occurred at Volcano Fuego on 14 September 1971. At present, there is a white steam cloud only. An investigation is underway."

Card 1295 (23 September 1971) Significant ash and lava emission; deaths reported

Fuego . . . has renewed activity and is spurting ashes and large amounts of lava. In view of this renewed activity, observation posts have been set up so authorities can take the proper measures for the evacuation of settlers close to the volcano in Scruintla Department. The lava flow was heading toward the Morelia Santa Sofía Farm and others are also threatened. Last week, this volcano spewed out large amounts of ashes and sand, causing damage to the plantations of several departments, but the population of San Pedro Yepocapa was the most affected. Two persons were killed there.

Card 1296 (27 September 1971) Review of activity; pyroclastic flows and ashfall

The following report from Samuel Bonis was telephoned to the Center today by R. Stoiber. "Volcano Fuego eruption: Sudden start 1445, 14 September 1971. Stopped 0300 15 September 1971 directed toward Yepocapa (SW wind). Tremors felt during eruption in Alotenango and Yepocapa. Very fine ash (powder) fell toward Alotenango. However, hot rocks and boulders came down the Barranca Honda toward Alotenango and reached La Reunión next to the Finka Capetillo.

"People called this lava but really it was a hot mixture of ashes and boulders. Coarse sand and gravel fell on Yepocapa more or less 8 km W of the crater to a depth of 30 cm. 5-cm-diameter scoria also fell here. Ash fell in Tapachula on the Mexican border and also was reported in Quezaltenango and in San Marcos.

"Rough calculations from Guatemala City by experienced geodocist estimates flowing molten material was thrown up to 1,000 m above the crater—black ash cloud much higher. All observers agree this was the most spectacular eruption in memory (at least 70 years). I don't think any lava flows produced; summit crater somewhat modified. Current activity minor or variable white vapor from summit crater. One killed and ten percent of the houses in Yepocapa with roofs caved in from the weight of the ash."

Information Contacts: Card 1290 (17 September 1971) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.
Card 1295 (23 September 1971) Samuel Bonis, Instituto Geografico Nacional, Guatemala; National Radio Service, Buenos Aires, Argentina.
Card 1296 (27 September 1971) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.

03/1973 (CSLP 24-73) Fine ash from February-March eruption falls in a 70-km radius

Card 1573 (01 March 1973) Ash column rises to height of 12 km on 22 February

The following report was received by R. Stoiber from Samuel Bonis on 28 February. "22 February Fuego started throwing fine ash to a height of about 12,000 m. This was accompanied by ash flows down the Barranca Honda. Activity continues. Prior to this there has been almost continuous gentle steam emission since the strong September 1971 eruption."

Card 1583 (16 March 1973) Ashfall in a 70-km radius during February-March eruption

The following report was received by R. Stoiber from Samuel Bonis on 15 March 1973. "Volcano Fuego erupted from 22 February to 3 March 1973. Most of the activity occurred between 23 February and 1 March. Fine ash was blown in a 70 km radius to the W, S, and E. Maximum thickness on the lower slopes of the cone was 1.5 cm. Voluminous ash flows came down canyons on the SW, S, and E slopes. There was no major damage."

Information Contacts: Card 1573 (01 March 1973) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.
Card 1583 (16 March 1973) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.

10/1974 (CSLP 134-74) Strong eruptions and heavy ashfall

Card 1955 (15 October 1974) Strong ash eruptions on 14 October

The Fuego volcano renewed its activity at 0400 on 10 October 1974, with tiny eruptions of ash and flows from the summit crater. Activity increased markedly at 0200 on 14 October, with very strong ash eruptions. Further investigations are underway.

Card 1967 (22 October 1974) Heavy ashfall damages crops and destroys homes

"The Fuego volcano renewed its intensive activity on 14 October at 0200. Ash clouds were thrown about 7 km above the vent. SE winds deposited 33 cm of ash 9 km to the W and 5 mm were deposited 60 km away. Traces of ash were carried to the Mexican border 150 km away. A preliminary estimate for the volume of ash is 0.1 km3 as of 20 October. Voluminous hot ash flows rushed down the canyons on all sides of the cone, especially Barrancas Honda, Las Lajas, Jute, Ceniza, and Santa Teresa. A renewed eruption lasted from 2145 on 17 October to 0030 on 18 October. Volume of ash from this eruption will probably prove to be greater than the 14 October episode. Field investigations are continuing.

"Thousands of people have abandoned their homes and many roofs have caved in from the weight of the ash. Communications and roads are disrupted. This year's crops over a large area have been destroyed and grazing areas have been buried. Although there have been few casualties, the eruption will take its unpublicized toll when malnutrition takes effect."

Card 1971 (29 October 1974) Minor emissions punctuated by strong ash eruptions; ashfall 200 km away

"Volcano Fuego continues in activity with generally gentle steam and light ash emissions, punctuated by strong ash eruptions on 13, 17, 19, and 23 October. Ash has been carried at least 200 km to the N and W. Ten centimeter lithic fragments were thrown 5.5 km to the SW by a one-hour episode on the 23rd, depositing 5 cm of ash 9.5 km to the SW.

"Major ash flow activity has decreased. The intermittent strong blasts, especially the showers of lithic fragments, have driven off many of the strong-hearted who had remained behind to clean their roofs and care for their livestock. Many crops have been ruined as far as 100 km to the NW. If this eruption follows past patterns, it should diminish in intensity. Field investigations continue."

Information Contacts: Card 1955 (15 October 1974) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.
Card 1967 (22 October 1974) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.
Card 1971 (29 October 1974) Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.

12/1974 (CSLP 171-74) Unusual sky observations from many locations; pilots observe dust layer

Card 2034 (26 December 1974) Unusual sky observations from many locations; pilots observe dust layer

"In mid-November bluish ashen daylight skies and beautiful twilight glows were noted over Baja, California and southern Arizona. The dust stratum is probably from the continuing November eruption of Fuego in Guatemala." (excerpt from note submitted to Science by A.B. Meinel and M.P. Meinel, University of Arizona, Tucson).

Since 26 November ultracirrus has been seen near Boston around sunset, attaining a pinkish color about 15 minutes after sunset. At dusk on 6 December and especially at dawn on 7 December the sky became glowing red and measurements indicate twilight conditions as after the Agung eruption of 1963. In Puerto Rico the sky radiance at 0.7 microns was higher at 3.5° solar depression than at 2° solar depression. Pilots observed a dust layer at about 20 km and a similar height was measured by LIDAR at NASA Langley (Applied Optics, January 1975).

As after the eruptions of Krakatau in 1883 and after Agung the dust may overspread the northern hemisphere, terminating a period of clean stratosphere, and abate within two to three years.

Information Contacts: F.E. Volz, Optical Physics Lab, Hanscom Field, Bedford MA, USA.

01/1975 (CSLP 171-74) Optical effects at sunset indicate volcanic dust in the atmosphere

Card 2043 (10 January 1975) Optical effects at sunset indicate volcanic dust in the atmosphere

On 28 and 29 December 1974, a "volcanic dust sunset" was observed by Dr. Lamb at Ketteringham (52°34'N, 01°12'E), England. In particular, the purple patch and other colors of the background sky were observed at the proper elevations (cf. figure 1(b), p. 433, Philosophical Transactions of the Royal Society, vol. 266, No. 1178 of 1970, and the Krakatao 1883 Royal Society Report). The timing on 28 and 29 December was about 40-60 minutes after sunset, which places the illuminated layer at around 22 km height. This is the first time Dr. Lamb observed these optical effects since some time in 1964 when they were last visible in the United Kingdom after the Bali eruption. A colleague at the same institution noticed the same effects independently of him.

"The sky around the sun appeared abnormally white when the sun was at a slightly higher elevation, both in the morning and in the evening on the days concerned. On 28 December the rising moon was also abnormally white, although the sky was clear, and the background sky had an unusually leaden hue (purplish dark gray rather than black) for some hours. Such effects were hardly discernable on 30 December and thereafter. Hence, we are not (or not yet) discussing a uniform veil of material in the stratosphere."

Information Contacts: H.H. Lamb, Climatic Research Unit, University of East Anglia, Norwich, England.

08/1975 (CSLP 134-74) Sporadic explosions and ashfall through 4 August

Card 2263 (25 August 1975) Sporadic explosions and ashfall through 4 August

On 28 May 1975, trace amounts of fine ash fell on Yepocapa, 8 km W of Volcan Fuego. The activity started at 0800 hours local time and ended during the night. This gentle eruption was probably accompanied by small ash flows on the upper southern slope of the cone.

Sporadic explosions have been heard coming from the summit crater during the period 23 July to 4 August. Small possible sah flows were reported on 29 July. The summit of the cone has been clouded for most of these months so that continued small ash flow activity cannot be confirmed. A stronger explosion accompanied by shock tremor was felt in Yepocapa at 2130 hours on 30 July.

On 4 August a tiny trace of ash powder fell on Yepocapa during the morning, starting at about 0800 hours. This was accompanied by a strong sulfur odor and columns of vapor shooting out of the crater. A red glow was seen in the crater region at dawn. Strong explosions were heard at about 1000 and 1500 hours, the latter accompanied by shock tremors. Apart form continuous vapor emission, this has been the only activity since the major eruption of October-November 1974. There has been no unusual activity since 4 August 1975.

Information Contacts: Samuel Bonis, Instituto Geografico Nacional, Guatemala; Richard Stoiber, Dartmouth College, USA.

10/1975 (NSEB 01:01) Occasional ash emissions in September and October

Unusual activity on Fuego, aside from minor vapor emissions, started the night of 19 September. Since that time there have been occasional emissions of dark gray to black ash clouds. The ash was either dissipated as dust in the atmosphere or fell on the upper slopes of the cone. A trace fell on some populated areas but was insufficient for collection. A large ash cloud was observed on 2 October at 0830, and on 11-12 October ash, brownish-gray in color, fell on Antigua.

Further Reference. Yuan, A.T.E., McNutt, S.R., and Harlow, D.H., 1984, Seismicity and Eruptive Activity at Fuego Volcano, Guatemala: February 1975-Januaryuary 1977; JVGR, v. 21, p. 277-298.

Information Contacts: D. Willever, Antigua; S. Bonis, IGN.

03/1977 (NSEB 02:03) Steam plume from a S-flank vent

On 3 March, a steam plume was emitted for 5-10 minutes from a vent about 200 m below the summit crater on the S flank. The plume first appeared to be dust-colored then turned white. About 2 weeks earlier, road workers on the N flank had reported a small saline brook originating below the summit crater.

Information Contacts: P. Newton, Antigua.

04/1977 (NSEB 02:04) Small ash eruption on 19 April

A small ash eruption from Fuego occurred at about 1100 on 19 April.

Information Contacts: P. Newton, Antigua.

09/1977 (NSEB 02:09) Ash emission almost continuous during 12-13 September

Steam clouds containing a little ash rose about 1,000 m above the summit, beginning before dawn on 11 September. The eruption was preceded by felt earthquakes on 6 September at 2206 and 9 September at 0420 and was accompanied by harmonic tremor. On 12 September, emission of voluminous brown to black clouds was nearly continuous, frequently broken by 10-20-second intervals of quiescence. At 2130, incandescent bombs and ash were ejected. Ash emission was continuous on 13 September and harmonic tremor amplitude increased. Some ash fell on the W flank, at Yepocapa. The eruption had ended by 14 September [but see 2:10].

Information Contacts: S. Bonis, IGN; R. Stoiber, Dartmouth College; D. Harlow, USGS, Menlo Park, CA; P. Newton, Antigua; D. Shackelford, CA.

10/1977 (NSEB 02:10) Steam and ash emission continues intermittently through late October

Steam and ash emission has continued intermittently through late October. A substantial increase in activity 19-20 October was reported. Columns of dark gray ash were ejected at about 1-hour intervals on 24 September, accompanied by rumbling. Activity declined the next day but similar ash ejections resumed on 26 September, lasting until evening. At 2000, loud rumbling was succeeded by a small eruption of incandescent ash and bombs, accompanied by hot avalanches that moved a short distance down canyons on the upper flanks. Persons near the volcano felt an earthquake 2 hours after the eruption and several more the next day. Incandescent ash was ejected on 28 September until 2200 and thick ash, accompanied by loud explosions, was emitted for several hours the next day. A moderate ash eruption, including small hot avalanches, was visible through thick cloud cover on 2 October. Two days later, several explosions at around 1630 produced black ash clouds. About 3-4 brown to black ash puffs per hour were reported on 7 October, accompanied by a red glow at night. Incandescence was also reported during the night of 9 October.

Explosions increased markedly on 19 October, producing minor local ashfalls from clouds that rose 1,500 m above the vent, and continuous small hot avalanches, which were again restricted to canyons on Fuego's upper slopes. Maximum activity was on 20 October, when a trace of ash fell on villages SW of the vent. Intermittent small steam, ash, and ash flow eruptions continued on a reduced scale as of 26 October.

Information Contacts: S. Bonis, IGN; R. Stoiber, Dartmouth College.

11/1977 (NSEB 02:11) Increased activity continues through mid-November

Increased activity was continuing in mid-November. Only occasional observation of the volcano has been possible because of heavy cloud cover. 29 October: Weak ejection of incandescent material at 2230; no hot avalanches observed. 3 November: Emission of large volumes of steam under considerable pressure. 5 November: Moderate steam emission from the summit crater and a thin, 60 m high steam column issued from a vent high on the NE flank. 7-9 November: Weak steaming from both vents 7 November, increased slightly on the 8th. Ash ejection 9 November was mainly from the summit crater. 12 November: Steam and ash emission from the summit crater and steaming from the NE vent. 13 November: Intermittent 250-300 m steam and ash clouds from the summit crater during the day. Between 1915 and 1930, bright red incandescent material was ejected. 14 November: Steaming during the morning, succeeded by intermittent ejection of dark gray and black ash in the afternoon. 15 November: Steam emission from the summit crater, and clouds of steam from the upper portion of a canyon on the E flank, possibly from a fresh hot avalanche deposit. 16 November: Weak felt earthquake at 1455, accompanied by noise. 17 November: Intermittent bursts of dark gray and black ash from the main crater visible during the morning.

Information Contacts: P. Newton, Antigua.

12/1977 (NSEB 02:12) Intermittent black ash emissions and glow

Cloudy weather continued to hamper observations through December, but black ash emission was frequently visible during the day and glow or small incandescent eruptions at night.

Brief, intermittent ejection of black ash occurred 20 November and was occasionally visible through clouds 24-28 November. Weak glow during the night of 20 November brightened the next night and was weak again on 22 November. Felt earthquakes on 23 November preceded incandescent tephra ejection during the night.

On 29 November, activity had declined to steaming within the crater without night glow, which persisted until the afternoon of 2 December, when felt earthquakes preceded black ash ejection. Intermittent, 5-minute incandescent eruptions were seen that night and more ash was ejected the next morning. Glow was seen on 6 December and weak black ash emission was occasionally visible through the 9th.

Visibility was poor during the next 10 days. Black ash was seen on 12 and 14 December, but the volcano was only steaming on the 17th. A glow was observed on 18 December and intermittent black ash puffs were seen during the next 3 days. Ash clouds rose more than 650 m above the crater during the mornings of 22 and 23 December, but activity had weakened by the afternoon of the 23rd. On 24 December, 200-m ash clouds were emitted in the afternoon and there was a glow in the crater at night. The next day, intermittent ash puffs reached 600 m above the crater and incandescent eruptions, accompanied by a small glowing avalanche, occurred at night. Ash puffs continued through 28 December, and small incandescent eruptions were seen that night.

Information Contacts: P. Newton, Antigua.

01/1978 (SEAN 03:01) Largest eruption since 1974

Intermittent activity continued through late January culminating in the largest eruption since 1974. The 29 December-28 January information is from Paul Newton, and the 29 January-1 February information was reported by Samuel Bonis to Richard Stoiber.

29 December-15 January: Black (primarily) to gray ash clouds were emitted at low velocity from at least 3 vents within the summit crater. Ash fell mainly on the upper N flank, but some fine material fell several kilometers downwind. Incandescent ejecta was visible above the summit on 30 December, and l, 5, 7, 9, and 15 January. Incandescent activity was weak except on the 15th, when bombs were ejected and ash fell on the E flank. Weak steaming from a small vent on the upper E flank was observed on 9 January. 16-17 January: Mostly steaming, with a little black ash emission. 18-22 January: Low-velocity black ash emission to a maximum height of about 370 m above the crater. 23-28 January: Activity decreased markedly to weak steam emission.

Weak earthquakes, accompanied by rumbling, were felt at 2015 on 29 December, 2130 and 2200 on 5 January, between 1100 and 1115 on 9 January (2 events), 1100 and 1215 on 15 January (lasting about 4 seconds each), and 0600 on 20 January (followed by black ash emission). Larger events were felt on 19 January at 2015 (15 seconds) and 2320 (about 4 seconds).

"Fuego had its strongest eruption since 1974 from 29-31 January. The eruption column reached about 4000 m above the crater, and 1 mm of ash blanketed the ground 5 km SW of the vent. Small nuées ardentes flowed down the canyon of the Rio Taniluya, on the SW flank of the volcano. Fuego was inactive at sunrise on 1 February."

Information Contacts: P. Newton, Antigua; S. Bonis, IGN; R. Stoiber, Dartmouth College.

02/1978 (SEAN 03:02) Two new lava flows, the first since 1966

More prominent Vulcanian activity 28-31 January was followed in February by a lava flow, uncommon in Fuego's history. Since Fuego's first recorded event, in 1524, less than one in four eruptions have been accompanied by a lava flow.

The following information, provided by Paul Newton, supplements the report last month. Weak glow in Fuego's summit crater was observed at 1800 on 28 January, beginning 3 days of strong explosive activity. By 2000, bright orange-red incandescent material could be seen in the crater and glowing avalanches flowed down the flanks, accompanied by large incandescent blocks. The next day, black to gray-black ash was emitted steadily to several hundred meters above the crater. Strong, low-pitched rumbling was heard and a few weak felt shocks occurred. At night, glowing avalanches were again visible and incandescent material rose a short distance above the crater rim. On 30 January, frequent strong rumbling accompanied emission of black to gray-black ash to an estimated height of 2,300 m above the crater. After sunset, incandescent ejecta including large light orange to bright red blocks rose as much as 250 m above the crater and large glowing avalanches flowed down the flanks. The eruption began to weaken after dawn on the 31st. Ash ejection had become intermittent by 1630 and had stopped by 2200. Crater glow had dimmed to a dull red. The next morning, activity was limited to emission of a small brown-white to white plume.

The following is a report by William I. Rose, Jr. "Throughout February, Fuego has been repeatedly visited by a plume-sampling aircraft from NCAR. Lava flows were first observed on 9 February in two 30 m-diameter craters 0.1 km SW of Fuego's summit. The flows had advanced 0.5 km down the SW flank of the cone by 11 February and the lava craters showed continuous incandescence. Hot debris slides from the toes of the two flows had cascaded more than 3 km down the valley of the Río Taniluya by 22 February. Small (100-500 m-high) ash eruptions (3-15/hr) occurred from the summit crater as the lava flow activity continued. On 24 February the three vents were observed in simultaneous activity. The summit crater was erupting a continuous stream of gas and fine ash, while the two lava vents exhibited lava fountaining interspersed with dark ash explosions. The rate of lava flow extrusion appeared to be increasing."

Further Reference. Rose, W.I., Jr., Chuan, R.L., Cadle, R.D., and Woods, D.C., 1980, Small Particles in Volcanic Eruption Clouds; American Journal of Science, v. 280, p. 671-696.

Information Contacts: W. Rose, Jr., Michigan Tech. Univ.; P. Newton, Antigua.

03/1978 (SEAN 03:03) Ash emission continues

Emission of black to gray ash continued through March. Cloudy weather prevented observations on 9 days during March, and no report on the lava flows was available. Intermittent incandescence was seen during the evening of 26 February, but no incandescence has been observed since then. Activity was limited to weak steaming on 28 February and 22, 25, 27, and 29 March.

Strong activity occurred on 25 February, and 2, 4, 23, and 30 March. Ash columns rose about 1000 m above the summit at 1700 on 25 February, and from 0600 until clouds obscured the volcano at 1100 on 2 March. On 4 March, black ash was emitted to 1250 m above the vent for over 3 hours, beginning at 0600, but the column had become lighter colored by 1100 when clouds prevented further observation. Between 0730 and 1030 on 23 March, fine ash and vapor reached 1800 m above the vent, while heavy ashfall occurred on the upper N flank. At 0600 on 30 March, emission of black ash from the main crater was accompanied by a vapor plume from the N vent. Shortly before 0800, a 2300-m black column was emitted, appearing to originate from both vents, and a hot avalanche flowed down a canyon on the E flank. The eruption could be seen above the clouds until 1100, when visibility became completely obscured.

Earthquakes were felt in Antigua, 17 km NE of Fuego, on 4 March at 0550 (moderately strong) and 1137 (weaker); 13 March at 0130 (weak); 22 March at 0340 (weak); and 30 March at 1330 (strong, lasting 4 seconds).

Information Contacts: P. Newton, Antigua.

04/1978 (SEAN 03:04) Mild to moderate ash emission continues

Emission of black to gray ash continued through late April. Clouds and haze completely obscured the volcano on 9 days during April and limited visibility to only a few hours on most other days.

Activity usually consisted of mild to moderate emission of gray ash. Stronger activity occurred on 2 April, when black ash rose about 1000 m during the morning, but activity had declined by late afternoon. Dark gray ash emission was visible between 0730 and 0830 on the 20th (to 1000 m above the summit) and at about 1030 on the 23rd (to 550 m). Small amounts of fine ash fell on Antigua on 17, 18, 19, 21, and 25 April. Incandescence was seen before dawn on 15 and 20 April.

At 1120 on 15 April an earthquake centered approximately 15 km NE of Fuego was felt at intensity 3 in Antigua, 3 km from the epicenter, for about 10 seconds. A small 1.5-second event was also felt in Antigua at 1822 on 26 April.

Information Contacts: P. Newton, Antigua.

05/1978 (SEAN 03:05) Mild to moderate ash eruptions continue

Intermittent emission of gray to black ash clouds continued through late May. Clouds and dense haze totally obscured the volcano for 11 days of the 25-day reporting period (28 April-22 May), and visibility was limited to only a few hours on many other days.

Small incandescent eruptions occurred after sunset on 3 May, the only incandescent activity seen during the reporting period. Fine ash fell in Antigua on 7 May, then after 2 days of weak steam emission (8-9 May) and a cloudy day (10 May), ashfall in Yepocapa, 8.5 km NW of the summit, was reported on the 11th and 12th. Ash rose to more than 1400 m early on 13 May and to about 1100 m the next day, when simultaneous activity from 3 vents was observed and several small directed blasts from a fourth vent sent hot avalanches down a canyon on the SE flank. Ash fell on Antigua each day between 15 and 20 May, but the volcano was visible only for brief periods; maximum observed ash cloud height was about 1500 m, at 0900 on the 18th. Only 1 earthquake was felt in Antigua during the report period, a small shock at 1145 on 5 May.

Information Contacts: P. Newton, Antigua.

06/1978 (SEAN 03:06) Two new lava flows and a large ash cloud

A column of incandescent ejecta was seen above the summit after sunset on 22 May, but observed activity declined between 23 and 28 May to emission of steam and ash plumes (usually gray to dark gray) reaching a maximum height of 900 m. Ash fell on Antigua on 29 May, but clouds limited observation until evening. During the night of 29-30 May a red glow was seen over the summit, accompanied by occasional incandescent eruptions. Glowing avalanches flowed down canyons on the NE and SE flanks. After sunrise on the 30th, black ash could be seen discoloring a cloud bank 1,000 m above the summit before visibility was totally obscured at midmorning. Activity the next day was weak and no incandescence was observed.

The following information is from Samuel Bonis, David Harlow, and Keith Priestly (see 3:7 for 1-14 June observations). Fuego's eruption intensified on 15 June. Two viscous flows were extruded from the summit area and traveled slowly down canyons on the E and SE flanks, accompanied by vigorous ash ejection. This activity continued the next day, accompanied by almost constant rumbling. The ash cloud rose an estimated 3 km on the 16th and was seen by airline pilots from as far away as the Mexican border, about 170 km NW. At Yepocapa, 1-2 mm of ash fell in about 1.5 hours. By 17 June, lava extrusions had ended, and explosive activity was confined to weak ash emission, which was continuing on 19 June.

Information Contacts: P. Newton, Antigua; S. Bonis, IGN; D. Harlow, USGS, Menlo Park, CA; K. Priestly, Univ. of Nevada, Reno.

07/1978 (SEAN 03:07) Lava flows, hot avalanches, and explosions in June; activity declines in July

Between 1 and 6 June, activity was confined to weak steam and ash emission from the summit crater and vapor emission from a small subsidiary vent near the summit. During the late afternoon of 7 June, steam and ash clouds rose 1,100 m, and after sunset loud rumbling was heard for several hours. Activity was very weak on 8 June and clouds obscured the volcano on the 9th.

Several incandescent avalanches were observed flowing down a canyon on Fuego's E flank before dawn 10 June, and that evening more incandescent material was seen in the same canyon, as much as 725 m below the summit. Similar activity was observed 11-12 June, but during the morning of the 13th, only weak steaming was visible.

A lava flow moved slowly down the E flank canyon after sunset on the 13th, to about 550 m below the summit. The volcano was obscured by clouds on the 14th and much of the 15th, but lava was visible during the evening of the 15th. Activity intensified on 16 June. At 0700, three lava flows were moving down the E and NE flanks, and at 1100 a hot avalanche traveled several kilometers down the NE flank as ash rose 1,900 m from the summit crater. Felt earthquakes accompanied by loud rumbling occurred at 1400, followed by a 2,300-m ash cloud and hot avalanches at 1600. Throughout the evening, several streams of lava could be seen descending the E and NE flanks. Lava extrusion had ended by the next morning, but a few hot avalanches were observed.

Activity between 18 and 25 June consisted primarily of weak steam and ash emission, but some incandescence was seen above the summit on 19, 21, 24, and 25 June. A hot avalanche was observed early on 26 June accompanied by 1,200-m ash clouds. Incandescent material, possibly another lava flow, reached a level more than 1,000 m below the summit in 4 hours of evening activity. Incandescent ash rose about 800 m above the summit and loud rumbling was heard. Similar activity continued through the end of June, with frequent hot avalanches and accompanying vertical emissions rising as much as 2,200 m.

Powerful explosions were heard at 2230 on 30 June and at 0215, 0700, and 2300 on 1 July. The 3rd explosion produced a 2,200-m ash cloud; the 4th caused a strong air shock at the base of the volcano, and yellow to red ejecta including large blocks rose a short distance above the crater.

Poor weather conditions prevented observation of Fuego during much of July. The volcano was inactive during brief periods of visibility on 4 and 5 July, but incandescence was observed above the crater on the 6th and a glowing avalanche moved down the NE flank. Some incandescence was visible above the crater on 8 July. Activity was limited to weak steaming and a few ash puffs between 12 and 19 July. A hot avalanche flowed about 800 m down an E flank canyon on 21 July and ash rose about 1,000 m on the 21st and 22nd. On 23 July, the last day of observations reported here, only weak ash emission was observed.

Information Contacts: P. Newton, P. Alquijay, D. Willever, Antigua.

08/1978 (SEAN 03:08) More ash emission and hot avalanches; no new lava flows

Intermittent ash emission continued through late August, but no new lava flows were reported. The maximum observed ash cloud height was about 1,650 m, on 18 August. Summit glow and ejections of incandescent material were often visible at night.

Numerous hot avalanches moved down the NE, E, and SE flanks during the late afternoon and evening of 24 July. Small incandescent ejections were seen the next night and dark gray ash rose to 1,100 m the morning of the 26th. Activity had declined by that evening, and was characterized through the end of July by the emission of small, dense, brown to black ash puffs. Occasional jets of incandescent material from the main crater and fumarolic activity from a vent near the main crater were seen 29 July.

Activity declined further in early August. Very weak black ash emission during the morning of 1 August was succeeded by steaming that continued intermittently through the next day. Ash emission resumed 3 August and jets of incandescent ejecta were seen at night. Ash clouds rose about 800 m on 4 August; each ejection lasted 3-4 minutes followed by about 30 minutes of quiescence. Clouds obscured the volcano 5-9 August.

A series of loud rumbling sounds was heard in Antigua during the late afternoon and evening of 9 August. Another rumble was heard early 10 August, accompanying the ejection of an 1,100-m black ash cloud. Intermittent ejection of black ash continued for the next several days. Clouds rose to 1,200 m on the 12th and 1,600 m on the 13th, and a small earthquake was felt in Antigua at 2214 on 12 August. Incandescent ejecta were seen after sunset on 10, 11, 13, 14, and 15 August. A hot avalanche traveled about 600 m down the E flank on 17 August.

Immediately after a magnitude 5.4 earthquake at 0936 on 18 August, 51 km W of Fuego, ash emission became more voluminous. That evening ash clouds reached about 1,650 m above the summit. Early on 19 August, ash rose 1,100 m above the summit and a hot avalanche moved about 550 m down the SE flank late in the afternoon. Incandescent material was occasionally seen during the evenings of 19-21 August, but clouds prevented daylight observations. Activity weakened 22-23 August (the last days of observations reported here), with weak steaming and ash emission from several summit area vents.

Information Contacts: P. Newton, Antigua.

09/1978 (SEAN 03:09) 5,500-m ash cloud and hot avalanches; probable dome visible above crater rim

Intermittent emission of ash and some hot avalanches persisted through September. Ash clouds reached a maximum observed height of 5,500 m, on 3 September.

The weak activity of 22-23 August continued on the 24th. Activity strengthened on 25 August, and between the 25th and 28th varied from emission of thin grayish clouds about 1,000 m high, to ejection of larger, more ash-saturated clouds about 1,500 m high. On 29 August, intermittent bursts of dense black ejecta were thrown slightly above the crater rim during the morning, and incandescent ejecta rising to about 550 m were seen after sunset. Weak ash emission was briefly visible through clouds the next day, then clouds and rain obscured the volcano until 2 September. That evening, incandescent material, including large blocks, was thrown to about 550 m. An avalanche of yellow-orange to red material, originating from the toe of what appeared to be a short lava flow just below the crater rim, traveled down a canyon on the E flank. After midnight, a nuée ardente traveled down the same E flank canyon to the foot of the volcano. Between 0630 and 0930 on 3 September, a cauliflower-shaped eruption cloud rose to 5,500 m above the crater and nuées ardentes flowed down the E flank canyon. Ashfall was confined to Fuego's flanks. Rumbling and felt seismicity accompanied the activity during the night of 2-3 September and the morning of the 3rd. Clouds obscured the volcano for much of 3 September, but a 2,200-m eruption cloud and a large red glow were visible above the crater in the early evening.

Activity had declined to weak steam and ash emission early on 4 September, although incandescence was seen through clouds that night. From 4 to 14 September, clouds of varying ash contents reached a maximum observed height of 1,100 m (on the 8th) but most rose only a few hundred meters and there were periods of quiescence. A small earthquake was felt for about 3 seconds in Antigua at 1305 on 7 September, and a much larger, magnitude 5.5 (mb) event, 67 km WNW of Fuego, was felt there at 1724 on 10 September, continuing for nearly 1 minute. A rounded dome or cone could be seen protruding over the top of the crater rim.

Glow was seen over the crater after sunset on 14 September and intermittent incandescent activity occurred the next night. On 16 September, voluminous dark gray ash clouds were emitted to 1,100 m and a thunderstorm generated large lightning bolts that struck Fuego's crater just before sunset. Similar ash ejection occurred on 17 September. Incandescence was seen above the crater that night, as hot avalanches traveled down a canyon on the E flank. Black and gray ash rose as much as 2,000 m on the 18th and intermittent incandescence was visible at night. Rain and clouds prevented further September observations.

Information Contacts: P. Newton, Antigua.

10/1978 (SEAN 03:10) Summit dome growing, but explosive activity declines

Fuego's eruption declined substantially in October. The summit dome noted last month continued to grow. Fuego was steaming weakly on 23 September and a brief break in the clouds on the 24th revealed no activity. Voluminous steaming had begun by the morning of the 25th. That night, a glowing avalanche traveled about 550 m down a canyon on the E flank. After dawn on 26 September, steam rose slowly to about 1,100 m, then clouds prevented further observation. Weak steaming was seen after dawn the next day. Beginning before dawn on 28 September and continuing through the evening, nuées ardentes moved down the E flank canyon. Red glow and some small incandescent eruptions were visible at night. Heavy cloudiness prevented observations on 29 September, but brief glimpses of the volcano on 30 September and during the day on 1 October showed no explosive activity. Weak ejections of incandescent material after sunset on 1 October were separated by long periods of quiescence. After 1 October, no ash or incandescence was seen. Although the summit dome was clearly growing, other activity was confined to weak or moderate steaming from the summit crater, and occasionally from two smaller vents near the summit. The maximum steam plume height during the period was about 1,000 m. Small earthquakes were felt in Antigua at 1209 on 4 October and at about 0245 on 22 October.

Information Contacts: P. Newton, Antigua.

11/1978 (SEAN 03:11) Avalanches from new block lava flow; brief moderate Vulcanian activity

After a month of dome growth and weak steaming, lava flow extrusion began in late October and was continuing in late November.

The following is from Paul Newton. Fuego's activity was limited to weak steaming from 24 October until the evening of 28 October, when a loud explosion was heard at 1930. About 30 minutes later, avalanches of glowing ash and some large blocks began to travel down Barranca Honda (figure 1), a canyon on Fuego's E flank. Hot avalanches continued through at least 1130 the next day, accompanied by weak steaming. The SE side of the summit dome appeared "distorted" from Antigua. Clouds then obscured the volcano until 1830 when a glow was visible over the summit but hot avalanches had ceased.

Figure 1. Topographic map of the Fuego and Acatenango volcanic complexes, adapted by Chesner and Rose, 1984, from Alotenanga and Chimaltenango 1:50,000 quadrangle maps, Instituto Geográfico Nacional, Guatemala.

Only minor steaming was observed between 30 October and 4 November. The vapor column reached 700 m in height on 5 November. Incandescent avalanches resumed by the evening of 6 November, stopped by the next morning, then began again during the evening of the 7th and continued through 12 November, the last day of Newton's observations. Weak steaming and occasional emission of dark gray ejecta to a maximum observed height of 500 m accompanied the avalanches. Earthquakes were felt in Antigua at 1224 and 1312 on 30 October, and at 0030 on 31 October.

The following report, by Dennis Martin, is based on observations from the E side of Fuego 19-20 November, and from Alotenango (at Fuego's NE foot) beginning 21 November, plus conversations with local residents. "An incandescent lava flow about 300 m long extruded from a vent just E of and below the summit was flowing down Barranca Honda. Where the slope within the barranca steepens to more than 60°, the flow formed a spectacular lava cascade where incandescent lava blocks dropped hundreds of meters. Extending about 3 km further down the Barranca to elevations of about 2 km was a block avalanche fed by accumulations of incandescent blocks from above. This avalanche continually oversteepened and produced its own incandescent cascades. At night, incandescence from the block avalanche disappeared below about 3 km elevation. Because of accumulations high in Barranca Honda, a block avalanche had began to advance down an adjacent canyon (N of Barranca Honda) in mid-November. Both avalanches had reached a point about 6 km from National Route 14, where the nearest people live. Weak, sporadic lava fountaining at the summit mound and gas emission from an apparent 500-m-long N-S fissure accompanied the lava flow.

"A moderate Vulcanian eruption, similar in intensity to the 29-31 January events began at 0030 on 21 November. The eruption cloud rose more than 2 km and was blown WSW and W. Incandescent blocks were thrown to a height of a few hundred meters. An apparent ash flow descended the Barranca Honda at 0430. The loudest of nearly continuous audible explosions heard at Antigua occurred at 0600, but by 0900 the eruption was clearly decreasing in intensity and continued to do so for the rest of the day. By the evening of 22 November, the Vulcanian activity had declined to 1-2-minute explosions at about 2-hour intervals. The lava flow activity of the previous weeks continued during the Vulcanian eruption."

Information Contacts: D. Martin and W. Rose, Jr., Michigan Tech. Univ.; P. Newton, Antigua.

12/1978 (SEAN 03:12) Lava flow stops, but intermittent fountaining and ash emission persist

Information for the period 23 November through 5 December is from Don Willever and Paulino Alquijay, compiled by Paul Newton. Observations from 6 through 18 December are by Paul Newton. Clouds frequently obscured the volcano, permitting only brief views of the summit area on many days.

After the moderate Vulcanian eruption of 21 November, activity had declined to occasional explosions and intermittent ejection of small amounts of incandescent material by the night of 22 November. No activity was visible when clouds briefly dissipated on 23 November. Between 24 November and the evening of 2 December, steam and ash clouds, usually white or gray but occasionally black, were ejected intermittently from the main crater, and steam was emitted from the N-S-trending fissure extending northwards from the summit. The steam and ash clouds usually rose only a few hundred meters, but an 1,100-m column was seen early on 28 November. A weak glow could be seen over the crater at night, but no lava fountaining or flows were reported.

Lava fountaining from the summit crater was observed after sunset on 2 December. The next night, incandescent material was visible in Barranca Honda, the principal lava flow channel on Fuego's E flank. Intermittent steam and ash emission, similar to the 24 November-2 December activity, was reported on 4-5 December. Clouds prevented observations on the 6th, but lava was seen in Barranca Honda on the morning of 7 December. Only weak steaming occurred on 8 December. Cloudiness obscured the volcano until after sunset on the 10th, when incandescent material rose a short distance above the summit. Low but voluminous black clouds were ejected the next day, then weather clouds prevented observations on 12 December. Activity was weak during the morning of the 13th, but frequent bursts of incandescent ejecta were thrown more than 500 m above the crater after sunset. Ejection of incandescent material was visible each night through 18 December, the last day of observations. Dense gray ash clouds rose about 700 m above the summit. Block avalanches, or rising dust produced by them, were seen in Barranca Honda on 15 and 16 December.

The following is from a report by Dennis Martin. "By 16 December, the summit mound seemed to have grown markedly, perhaps more than 100 m in height since 21 November. Between 11 and 16 December, ash-laden clouds were ejected at intervals of a few seconds to a few minutes, to a maximum height of approximately 1 km. Most clouds rose only a few hundred meters and were blown away by predominantly westerly winds. The duration of explosive intervals varied from 1 second to 2 minutes. At night, fountains of molten lava thrusting up to a maximum of 750 m could be seen within the ash-laden gray clouds. These incandescent blocks cascaded in a spectacular display from 100 to 1,000 m down the flank. However, the incandescent lava flow and resulting block avalanche down Barranca Honda were no longer visible. A walk up the Barranca Honda on 13 December confirmed that the block avalanche had stopped at approximately 2,600 m elevation. The new lava is a vesicular, olivine-bearing basalt like previous Fuego magmas."

Information Contacts: P. Newton, P. Alquijay, and D. Willever, Antigua; D. Martin, Michigan Tech. Univ.

01/1979 (SEAN 04:01) New lava flow and block avalanches

Sporadic ejection of ash clouds, sometimes accompanied by incandescent material, continued through early January. Lava flows and block avalanches moved down the E flank 6-8 January, then a pattern of intermittent ash emission and occasional fountaining resumed, continuing through 21 January. Fuego's summit was only briefly visible through clouds on many days of the 19 December-21 January observation period, but was totally obscured only on 3-4 and 12 January.

A thin ash column rose more than 1,300 m during the late afternoon of 19 December and a small ash flow moved down Barranca Honda the next morning. Low incandescent ejections were visible during the night of 21-22 December, but ash rose only about 0.5 km the next day. On the 23rd, voluminous ash clouds were ejected to about 1 km above the summit and there was a slight ashfall in Antigua. That night incandescent ejecta was again visible, and ash and small blocks flowed about 500 m down Barranca Honda. Ash clouds as high as 1,600 m were emitted on 24 December, but activity declined to minor steaming between the 25th and 31st. Ejection of incandescent material after sunset on 31 December and 1 January was succeeded by weak steaming through 5 January.

Before dawn on 6 January, lava began to flow down Fuego's E flank, dividing into separate streams that moved down Barranca Honda and several other canyons with a rolling, tumbling motion (see the description of lava cascades at Fuego in 3:11). Large blocks fell away from the main body of the flow, and a persistent brighter red area could be seen about 200 m below its source. On the 7th, a dense dust cloud rose from Barranca Honda and remained above it through evening, as lava continued to flow down the E flank. At 0400 on 8 January, a loud explosion was heard in Antigua and bursts of incandescent ejecta were thrown about 0.5 km above the crater. After dawn, ash clouds could be seen rising 2 km. Some of the ash was ejected from the base of the summit mound at an angle of about 30° from the vertical. Nuées ardentes flowed down the E flank. By late morning, the height of the ash columns was decreasing and ash emission had ended by late afternoon.

Several streams of lava continued to flow down the E flank through the 8th and block avalanching was prominent that night. However, only weak steaming was observed from 9 January until the night of 14 January, when small bursts of incandescent material were ejected from the summit crater and red glow in Barranca Honda was barely visible through dense haze. Weak ash emission on the 15th was succeeded by low but more voluminous ash clouds on the 16th, accompanied by a brown dust cloud that was present over the entire visible length of Barranca Honda. That evening, low but dense black clouds dropped ash onto the NW flank and brilliant bursts of lava and blocks were ejected nearly vertically from the foot of the summit mound to a height of about 0.3 km. A block avalanche descended Barranca Honda, then clouds prevented further observations. Similar but slightly stronger activity was seen on 17 January. Only weak steaming was visible during the day on the 18th, but at night bursts of lava fed block avalanches that traveled almost 1 km down Barranca Honda. Intermittent dark gray to black ash columns rose more than 1,100 m on 19 January. A light fall of fine ash on Antigua obscured the volcano from view on 20 January. The next morning, low lava fountaining was visible before dawn. Ash clouds rose more than 2 km by the evening of the 21st, accompanied by moderate ash emission from the base of the summit mound, at an angle of 40° from the vertical.

One large and several small earthquakes were felt in Antigua during the observation period. The largest was a magnitude 5.5 event centered 67 km SE of Fuego on 12 January.

Information Contacts: P. Newton, Antigua.

02/1979 (SEAN 04:02) More block lava down the E flank

After considerable lava extrusion and ash emission in early to mid-January, Fuego's activity was confined to weak steaming between 24 January and 7 February. Clouds obscured the volcano 22-23 January and from 8 February until sunset the next day.

Renewed visibility late on 9 February revealed red to bright orange-yellow block lava flowing down Barranca Honda, a canyon on the E flank. Large blocks bouncing from wall to wall of the canyon could be seen from Antigua. The next morning, dense black ash clouds were ejected, obscuring the summit area, and white vapor clouds reached a height of 2.5-3 km above the summit. By nightfall, black ash emitted from two vents formed a thin column about 1 km high and white vapor moved upwards about an additional 1.3 km. Bursts of incandescent material were thrown more than 200 m above these 2 vents. A large amount of block lava flowed down Barranca Honda, but blocks did not bounce out of the flow as they had the previous night. Lava also flowed into a second canyon N of Barranca Honda. Later in the evening, less lava was moving down Barranca Honda, but large numbers of incandescent blocks were thrown onto the N shoulder, then disappeared from view down the W flank (not visible from Antigua).

Clouds prevented night observations 11-18 February, and no lava was seen in Barranca Honda in the daytime during this period. However, ash emission continued, reaching a maximum observed height of 1.5 km and frequently rising about 1 km. Eruption clouds decreased in height and their ash contents declined 16-17 February, and no ash rose above low summit-area weather clouds on the 18th.

About midday on 19 February, block lava could again be seen flowing down Barranca Honda, and low clouds of black ash were ejected from the vents. After dark, several streams of lava were visible, flowing down Barranca Honda, a canyon to the N, and an open area on the NE flank. Glowing blocks tumbled away from the flows. On 20 February, the last day of observations reported here, lava extrusion persisted and dense black ash clouds rose about 0.5 km.

No earthquakes were felt in Antigua during the observation period, but persons nearer the volcano felt some shocks and heard numerous rumblings.

Information Contacts: P. Newton, Antigua; UPI.

03/1979 (SEAN 04:03) Summit fissure forms and block lava extrusion resumes

The extrusion of block lava observed 19-20 February was no longer visible by sunrise on the 21st. Dark gray to black clouds were ejected sporadically that morning, rising as much as 500 m, but ash contents declined in the afternoon, and by 1930 no activity was visible. Only intermittent emission of vapor, sometimes containing a little ash, occurred 22-24 February, with columns reaching a maximum estimated height of slightly more than 1,000 m. Activity declined further, to low but voluminous steaming from vents on the E and SW sides of the summit cinder cone, on 25 February. Mild steaming followed for two days. Slumping on the SE side of the summit cone was first observed on the 27th. After clouds obscured the volcano on 28 February, sporadic ejection of gray steam and ash columns could be seen on 1 March. The columns rose as much as 1,400 m on the lst and more than 2,000 m on the 3rd. The summit showed no activity early on 4 March, after which a period of cloudiness prevented observations until the 9th.

Activity 9-13 March ranged from periods of very mild steaming to emission of ash clouds that rose to a maximum observed height of 1,500 m on the 10th. Significant quantities of ash could be seen falling on Fuego's N and E flanks on 13 March. The slumped area on the summit cone had become a clearly-defined, wedge-shaped fissure by mid-March, extending from near the summit to somewhat less than halfway down the SE side of the cone.

Extrusion of block lava resumed on 17 March, after three days of weak steaming. The flow first became clearly visible after sunset, but probably began at or before daybreak, appearing to originate from the base of the summit cone fissure. Lava moved about 0.5 km down Barranca Honda. Many large blocks tumbled down the canyon. At 1915 on 18 March, an explosion ejected incandescent tephra, including large blocks, to a height of about 500 m. Clouds obscured the volcano on 19, 20, and most of 21 March; continuing lava extrusion was briefly visible on the 21st. Explosive activity on 22 March, the last day of observations reported here, produced ash clouds that rose about 2,500 m, accompanied by spectacular lightning. Fine ash fell on Antigua.

Information Contacts: P. Newton, Antigua.

04/1979 (SEAN 04:04) Frequent ash emission and more block lava

Fuego's pattern of frequent ash emission and occasional extrusion of block lava continued through late April. Cloudiness obscured the volcano frequently during this period, as Guatemala's rainy season approached.

The strong explosive activity observed on 22 March had declined somewhat by the following morning, but ash emission remained voluminous for the next several days. Dense black ash rose as much as 0.7 km and vapor reached a height of 1.3 km. Ash fell on Antigua on 23 and 25 March.

Activity intensified on 29 March. During the early morning, a black eruption column was ejected to more than 1 km over the summit. By late afternoon (when cloud conditions again permitted observations) the height of the eruption column had decreased but heavy ashfall was occurring on the flanks. Sporadic ejection of incandescent tephra was visible after sunset, and a glowing avalanche traveled down the E flank. Block lava extrusion began the next day, probably by morning, when dust could be seen rising from Barranca Honda. By evening, slow-moving lava had flowed more than 0.5 km down the canyon, and some large blocks had tumbled from its upper end. Small amounts of incandescent tephra could be seen emerging from a vent W of the summit cone.

Clouds obscured the volcano for most of the period 31 March-5 April. A dark gray eruption column, about 0.5 km high, was briefly visible on 31 March, and mild to moderate steam emission could sometimes be seen in the mornings during the cloudy period. On 6 April, a glowing avalanche descended Barranca Honda, and steam and ash were sporadically ejected from the summit. Stronger ash emission occurred the next day, causing heavy ashfall near the summit. Vapor clouds rose higher than the ash, to 1.1-1.7 km. The fissure on the summit cone had been substantially filled by ash.

Small bursts of incandescent tephra, separated by 5-18-minute periods of quiescence, were seen during the evening of 7 April. Activity was limited to mild steaming during the day on the 8th, but low, sporadic ejection of incandescent tephra could be seen after sunset. A 4-5-second, very low-pitched rumble was heard in Antigua just before midnight. Ash fell on Antigua during each of the next 3 days, while the volcano was hidden by clouds. Between 12 and 14 April, gray ash and vapor were intermittently ejected, rising as much as 750 m. Ash content of the eruption clouds increased on 15 April. A new fissure that had formed in the top of the summit cone was the source of low emission of black ash.

At 0820 on 16 April, deep rumbling was followed by an explosion that produced a 2.1-km-high ash cloud. Poor weather prevented further observations on the 16th, but by the next morning, maximum ash cloud heights had declined to about 0.5 km. Some incandescent tephra was visible, falling a few hundred meters from the summit cone.

Although clouds obscured the volcano from 18-20 April, ashfalls in Antigua on each of these 3 days indicated continuing activity. When visible through clouds 21-23 April, ash emission was moderate, rising about 0.5-1 km. Better visibility on 24 April revealed ash ejection from the fissure at the top of the summit cone; ash rose about 0.5 km and white vapor as much as 2 km. Ash again fell in Antigua on 23-24 April, the last days of observations reported here.

Information Contacts: P. Newton, Antigua.

05/1979 (SEAN 04:05) Ash emission weaker; no new lava flows

Activity observed at Fuego during the 26 April-24 May reporting period was limited to intermittent and usually weak ash ejection. All of the ash appeared to originate from the summit cone fissure, but Newton suggests that significant quantities may also be ejected from vents on the W side of the summit area, not visible from his vantage point. Clouds prevented any observations on 25, 27, and 28 April and 2, 5, and 19-23 May, as well as limiting visibility to brief glimpses on many other days.

From 26 April through 9 May, Fuego's eruption column was gray to black, usually rising 0.5 km or less. Ash ejection was often intermittent, as on 3 May when low but voluminous ash clouds were emitted for 4- to 7-minute periods, separated by 5-8 minutes of quiescence. Windless conditions allowed the ash column to rise an estimated 1.4 km on 6 May and 1.6 km on 9 May. Fine ash fell on Antigua, 17 km NE of Fuego, on 1, 7, and 8 May. A hot avalanche appeared to descend about 0.5 km down an E flank canyon on 30 April.

A small earthquake, lasting less than 2 seconds, was felt in Antigua at 1700 on 9 May. Rumbles were heard there the next morning, at 0300, 0400, 0600, and 0630, the last of which was quite loud. After dawn, thick and voluminous ash clouds were ejected to about 0.5 km above the crater. By midmorning the plume was white, rising a maximum of 1.4 km in still air. That night, the only incandescent material observed during the reporting period was ejected to a short distance above the summit.

Activity similar to that of 26 April-9 May resumed on 11 May. Intermittent bursts of black ejecta rose about 0.5 km, accompanied by steady steaming. Larger ash clouds were ejected on the 15th (to 1.6 km) and 16th (more than 2 km), then activity declined on 17 May to mild steaming and a single burst of gray ash to about 0.5 km above the crater. During the 2 hours of visibility the next day, no activity was observed. What appeared to be dense white gas was twice seen flowing down an E flank canyon during this period, on 14 and 17 May.

Clouds obscured the volcano 19-23 May. A mild, 4-second earthquake was felt in Antigua at 0300 on the 20th and a single sharp shock at 2315 on the 21st. Residents of Alotenango, at the base of Fuego, had reported numerous rumblings and earthquakes during a 15-day period prior to 17 May.

Although fine ash fell on Antigua on 22 and 23 May, only a very small plume, rising less than 0.3 km, was seen on 24 May, the last day of observations reported here.

Information Contacts: P. Newton, Antigua.

06/1979 (SEAN 04:06) Brief strong incandescent tephra emission

Activity at Fuego remained intermittent and relatively weak during most of the 25 May-27 June reporting period, although vigorous ejection of incandescent tephra occurred on 20 June. Rainy season clouds often made observation of the volcano impossible, particularly in early June.

During periods of visibility between 25 and 30 May, Fuego's activity was usually confined to mild steaming from the summit. However, voluminous black ejecta rose about 3/4 km early on 25 May and about 0.5 km in the late afternoon of 30 May, the latter followed by a light ashfall on Antigua. On 2 June at 1615, a brown tephra cloud was ejected at high velocity to 2.5-3 km above the summit. The volcano was briefly visible late the next afternoon, but no activity was taking place.

Except for a 30-minute period on 7 June (when it was inactive) Fuego was obscured by clouds 4-11 June. Weak vapor emission was glimpsed through clouds on 12, 13, and 15 June. Ash ejection was seen twice between the 16th and 19th, to 0.3 km height early 16 June and to about 0.5 km 24 hours later, but the volcano was otherwise inactive.

On 20 June, weak emission of light brown ash to 400 m height was followed at 0930 by ejection of incandescent tephra to more than 0.8 km above the summit. Large yellow, orange, and red blocks fell on the flanks before clouds prevented further observations at 1030. Intermittent voluminous ash emission could be seen for the next four days, some originating from a vent W of the summit. Maximum cloud heights were about 0.7 km. When the volcano was next (briefly) visible, on 27 June, activity had declined to occasional steaming.

Information Contacts: P. Newton, Antigua.

07/1979 (SEAN 04:07) Intermittent tephra emission, some incandescent

Activity at Fuego increased during July. Voluminous ash clouds frequently rose more than 1 km above the summit, and incandescent tephra was seen on several occasions, but no new lava flows were reported.

During the afternoon of 29 June, an explosion projected a black eruption cloud to about 2.5 km height, but activity quickly declined to intermittent gray steam and ash emission. When the volcano was next visible, on 3 July, occasional low-velocity bursts of brown to black tephra rose about 0.7 km. Tephra rose only about 0.5 km the next day, but incandescent material was ejected a short distance above the summit that night. After Fuego was obscured by 2 days of clouds, ash emission was voluminous and steady early on 7 July, rising to about 1.5 km. Shortly after sunset, incandescent tephra rose about 0.3 km, and large blocks fell on the flank. This activity intensified 45 minutes later, some tephra reaching an estimated 1.8 km above the summit, then subsided after about 10 minutes. The next day a brief explosion produced a 2-km-high voluminous gray-black cloud, but otherwise only weak steaming was visible. During the early evening three loud explosions were heard from Antigua but the volcano could not be seen through clouds. Several explosions, similar to the one observed on 8 July, took place on the 9th, with clouds reaching maximum heights of 1.5 km. Ash fell on the flanks of Fuego and adjacent Acatenango. The S end of the summit fissure could be seen to have widened.

Activity ceased the evening of 9 July, and only weak steam emission was seen 10-13 July. A single explosion produced a 0.75-km-high gray cloud on the 14th. Clouds obscured the volcano the next day. On 16 July, weak steaming during the day was succeeded by 15 minutes of thick intermittent bursts of black ejecta, rising about 0.5 km. Two small incandescent ejections were seen after nightfall.

Clouds prevented observations 17-18 July. Brown eruption columns were seen above the clouds on three occasions 19 July, rising an estimated 1.5-2 km. After another cloudy day on the 20th, a 0.6-km black ash column was seen in a brief clear period on the 21st. On 22 July, sporadic bursts of brown tephra produced dense clouds that rose 1-2 km. Eruption cloud densities declined 23-24 July, and reached heights of 1 km or less.

Information Contacts: P. Newton, Antigua.

08/1979 (SEAN 04:08) Activity declines to weak fumarolic emission

The intensity and frequency of ash emission at Fuego began to decline in late July. By mid-August only weak steam emission was visible, a condition that continued through 21 August.

On 25 July, four small explosions in a 45-minute period produced dark gray ash clouds that rose less than 0.6 km, after 1 hour of inactivity earlier that morning. A similar pattern of activity was observed on 26 and 27 July, but ash clouds were more voluminous, and reached 0.8 km on the 27th. Only steaming took place on 28 July until late afternoon, when 3-4-minute bursts of gray ejecta, rising to more than 1 km above the summit, occurred at intervals of 10-30 minutes. The next day, long periods of quiescence separated voluminous, but ash-poor emissions lasting 2-4 minutes each. The volcano was inactive on 30 July and only weakly active the following morning, but at 1330 on 31 July, the largest explosion of the reporting period took place, producing a cloud that rapidly rose to more than 2 km. Weak steam and ash emission followed this explosion, and similar activity was visible on 2 and 3 August (after a cloudy day on 1 August).

From 4-7 August, steam and ash emission was very weak, and by 8 August was interspersed with periods of complete inactivity. No activity was occurring during 1-hour breaks in cloud cover early on 9 and 10 August. Clouds obscured the volcano 11-12 August, but clear visibility 13-15 August revealed no activity. Fumarolic emission from a subsidiary vent near the summit resumed on 16 August and was continuing on 21 August, the last day of observations reported here.

Information Contacts: P. Newton, Antigua.

09/1979 (SEAN 04:09) Activity limited to steaming but heavy rains produce destructive mudflows

From late August through late September the summit was usually obscured by clouds. When the volcano was visible (26-29 August, 4-7 and 11-13 September), only steaming took place, from some or all of several vents high on the E and ENE flanks. Two fissures, of approximately equal depth, emitted steam S of and slightly below the top of the summit cone. Although winds for the past 2 months have frequently blown from Fuego toward Antigua, no ashfalls have occurred there during that time, in contrast to earlier, more active periods.

Unusually heavy rains have caused landslides and widespread flooding throughout Guatemala, resulting in many deaths, major crop losses, and closures of main road and rail transportation routes. Secondary mudflows formed from tephra on Fuego's flanks have been particularly destructive, as far downstream as the coastal plain.

Information Contacts: P. Newton, Antigua.

10/1979 (SEAN 04:10) New crater high on S flank

Activity was again limited to steaming from the summit crater and several other vents high on the flanks between late September and late October. Steaming was occasionally quite voluminous early in the reporting period, but had weakened considerably and was interspersed with periods of inactivity by late October. A clear view of the summit on 18 October revealed that a new crater had formed a short distance from two fissures seen the previous month.

Information Contacts: P. Newton, Antigua.

02/1980 (SEAN 05:02) Fumarolic activity continues; summit area described

Paul Newton and Paulino Alquijay have continued to monitor Fuego from Antigua since last October. Intermittent vapor emission from the summit and several other vents high on the flanks continued through January. Vapor occasionally rose more than 1 km above the summit, but activity was often weak and there were periods of as much as four days when no vapor emission was visible from Antigua.

The following report from William I. Rose, Jr., is based on air and ground observations between 22 January and 10 February. "Fuego was in a state of continous gas emission, mainly from vents around the edges of the summit crater. The plume varied considerably in intensity, but on its most impressive days it extended many tens of kilometers. The intense fumarolic activity at and around Fuego's summit has produced a broad white and yellow zone of encrustations above about 3,500 m elevation. The crater itself was 35 m in diameter, symmetrical, and about 20 m deep."

Information Contacts: P. Newton and P. Alquijay, Antigua; W. Rose, Jr., Michigan Tech. Univ.

03/1981 (SEAN 06:03) Gas emission; no significant changes in the summit area

On 16, 17, and 18 February geologists visited the summits of Fuego and Acatenango Volcanoes. Comparisons of photographs of Fuego taken on this expedition to ones taken by W.I. Rose, Jr., in February 1980 showed no striking physical changes in the summit region. The main areas of gas emission, on the N and the SE sides of the main crater, were the same as in 1980. The SE area is a spatter vent from Fuego's last eruption in 1977-79. During the group's visit, gas was being emitted at a moderate, steady rate, as in early 1980. On 21 February, however, the group observed that there was a clear pulsation in the rate of emission, with a period of about 2 minutes. A light wind on the 21st allowed the gas plume to rise nearly vertically about 400 m above the crater. Around the crater rim there were only a few fumaroles in contrast to many in early 1980. New fumaroles had appeared around and atop an older irregular domal protrusion on the W flank of the summit.

Information Contacts: T. Bornhorst and C. Chesner, Michigan Tech. Univ.

01/1987 (SEAN 12:01) Incandescent tephra

In early January, incandescent tephra ejection was visible from Antigua, 18 km NE. Some tremor may have been associated with the January activity. Only block ejection and increased fumarolic activity were reported in early February. Fuego's last reported eruption began in September 1977 and continued through mid-l979. Moderate explosions fed tephra columns and small pyroclastic flows; a summit lava dome formed and lava flowed down the upper flanks.

Information Contacts: Dorothea Newton, Antigua, Guatemala; E. Sánchez, INSIVUMEH; Norman Banks and Michael Doukas, USGS.

05/1987 (SEAN 12:05) Earthquake swarm; deformation; vapor plume

About 78 microearthquakes were recorded at Fuego station (FG3), 5 km [SE] of the summit, between 1300 and 1500 on 8 June. Residents of the area reported that they did not feel any earthquakes. An electronic tiltmeter at the seismic station measured 8 microradians of deformation. On 10 June, a white vapor column was observed emerging from the crater.

Information Contacts: E. Sánchez, INSIVUMEH.

07/1987 (SEAN 12:07) Small plume; possible microearthquake swarm

By May, visible activity was limited to a weak white plume from the summit crater. A seismic station (FG3), 5 km SE of the summit at 1,500 m altitude, registered 30 microearthquakes with S-P <= 2.0 seconds during May and 40 in June. On 8 June, residents of Guatemala City observed a white vapor column extending hundreds of meters above the summit. This coincided with an apparent earthquake swarm and a 10 microradian change on the electric tiltmeter installed in March at the same location as the seismic station (12:05). During the following days, INSIVUMEH personnel installed portable seismic stations 10 km E and W of the summit (at Alotenango and San Pedro Yepocapa). These did not register any seismicity. INSIVUMEH geologists suggested that heavy rains on 8 June may have been responsible for the observed activity.

Information Contacts: E. Sánchez, INSIVUMEH.

08/1987 (SEAN 12:08) Gas emission and microearthquakes

Gas emission from the crater and nearby microearthquakes continued through July. Seismic station FG3 registered 50 microearthquakes with S-P <= 2.0 seconds. The tiltmeter, at the same site, did not show abnormal variation. A small fumarole was also active about 100 m below the crater on the E flank.

Information Contacts: E. Sánchez, INSIVUMEH.

01/1988 (SEAN 13:01) Gas plumes with some ash

A small increase in fumarolic activity was observed on 22 January. Gas plumes with some sand-sized ash were observed.

Information Contacts: E. Sánchez, INSIVUMEH.

01/1990 (BGVN 15:01) Strong gas plume extends several tens of kilometers from the summit crater

Geologists observed a vigorous and persistent gas plume that extended several tens of kilometers W from Fuego's summit crater during work at neighboring Acatenango on 6 January between 0900 and 1400. Frequent rock avalanches occurred in the upper parts of Barranca Honda, a steep E flank canyon.

Information Contacts: S. Halsor, Wilkes Univ; C. Chesner, Eastern Illinois Univ.

03/1990 (BGVN 15:03) Continuous gas emission; summit morphology appears unchanged since 1980

Overflights of Fuego were made on 15 and 16 February by volcanologists from INSIVUMEH and Michigan Tech. The following is from their report.

"Continuous gas emission was observed, with no evidence of any magma at the surface. The geometry of the summit crater and its surroundings (which influences the paths of pyroclastic flows during eruptive activity) was unchanged since 1980. COSPEC measurements of SO2 emission rates were made from the air, yielding 265 ± 33 t/d on 15 February and 120 ± 30 t/d on 16 February (3 and 8 determinations respectively). These rates are very similar to the 100 t/d measured in February 1980 and much less than the rates measured in February 1978 (660-1,700 t/d) when Fuego was actively erupting (Stoiber et al., 1983; reference under Santiaguito)."

Information Contacts: Otoniel Matías and Rodolfo Morales, Sección de Volcanología, INSIVUMEH; W.I. Rose, Jimmy Diehl, Robert Andres, Michael Conway, and Gordon Keating, Michigan Technological Univ, USA.

02/1991 (BGVN 16:02) Prominent plume; moderate SO2 emission

During an aerial survey on 10 February, no changes in crater morphology were evident since the previous overflight a year earlier (15:03). The plume remained prominent, and SO2 emission measured by COSPEC was 190 ± 21 t/d.

Information Contacts: Rodolfo Morales and Gustavo Chigna, Sección de Vulcanología, INSIVUMEH; W.I. Rose, Robert Andres, and Kimberly Kogler, Michigan Technological Univ., USA.

05/1992 (BGVN 17:05) Seismicity and continued fumarolic activity

An apparent harmonic tremor episode was recorded in mid-April, prompting the placement of several additional portable seismometers on the volcano in early May. Since then, several tectonic earthquakes have been recorded, but no harmonic tremor. Fumarolic activity continued in the summit crater.

Information Contacts: E. Sánchez, and Otoniel Matías, INSIVUMEH, Guatemala; Michael Conway, Michigan Technological Univ.

12/1996 (BGVN 21:12) A white-to-gray smoke column seen rising over the crater

During 12-19 November a white-to-gray column was observed rising 70-200 m above the crater; winds then dispersed it to the S over the volcano's flanks. On 20 November the column rose to 500 m and drifted E; the following day the column's height was 200 m and oriented SW. From 25 November to 12 December the column was again at 50-200 m height and blown toward the S and SW. During this observation period the Fuego-Acatenango seismic network recorded a few earthquakes up to M 1.

Information Contacts: Otoniel Matías, Seccion Vulcanologia, INSIVUMEH (Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hydrologia of the Ministerio de Communicaciones, Transporte y Obras Publicas), 7A Avenida 14-57, Zona 13, Guatemala City, Guatemala.

04/1999 (BGVN 24:04) Eruption on 21 May dropped up to 40 cm of ash on local population; small lava flow

Reports from INSIVUMEH described an eruption during late May 1999, the first from Fuego since 1987. At 1000 on 21 May observers noted that small quantities of ash fell on the cities of Villa Nueva, Barbarena, Cuilapa, Jutiapa, and Chiquimula. At 1800 on 21 May an eruption sent ash to the S, SE, and SW. The regional ashfall affected areas including the peak ~4 km N (Yepocapa), the cities of Alotenango, Escuintla, Santa Lucia, Cotzumalguapa, Palin, Amatitlán, and the slopes of Pacaya volcano. Ash thicknesses at proximal sites were 10-40 cm. At 2100 the activity diminished, but continued with moderate 3-minute explosions. The Aeronautica Civil recommended that planes should not go any closer than 40 km from the volcano. At 2200 a lava flow ~200 m long was seen on the W side of the Barranca Honda drainage. By this time, the atmospheric ash had settled, and the Aeronautica Civil recommended not flying closer than 15 km from the volcano.

INSIVUMEH reported that NOAA detected ash over much of Guatemala to 14-15 km altitudes. It was not possible to see the activity in the crater, and the meteorological conditions for the next 24 hours consisted of electrical thunderstorms with rain in the afternoon and evening. At 0530 the seismic station "FG" located in the FICA La Reunion, 3.5 km E of the crater, registered movement beneath the volcano. Every hour for three hours, explosions sent gases and moderate ash to heights of 600-800 m.

Information Contacts: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57 zona 13 ciudad de Guatemala 01013, Guatemala.

07/1999 (BGVN 24:07) Moderate Strombolian eruptions 21 May-1 September

Volcán Fuego erupted during late May 1999 (BGVN 24:04) for the first time since 1987. From 21 May through 1 September, Fuego generated moderate Strombolian eruptions. The interval between eruptive pulses was frequently 5-10 minutes; in some cases ash columns rose as high as 800 m above the summit. Ash fell up to 15 km away. At night, incandescent displays rose ~250-300 m above the crater rim. Fragmental lava ejected from the vent constructed a ~25-m-tall spatter cone that provided source material for hot rock avalanches, some with runout distances of several kilometers. Although seismicity remained weak, local residents heard very strong rumbling.

Prior to 15 July the activity hazard status of the volcano was Orange. This was downgraded to Yellow on 15 July only to be increased to Orange again on 19 July as of result a lava extrusion and frequent small ash eruptions starting around 1600 and continuing throughout the day. Small ash emissions occurred on 20-21 July. INSIVUMEH reported that 13 explosions occurred between 2300 on 20 July and 0300 on the 21st, sending some tephra up to 700 m above the summit. The hazard status was raised to Orange and pilots reported ash to altitudes of 5,500 m W of Guatemala City. For the next seven days, the volcano remained unsettled; NOAA reported that near-infrared satellite images displayed an occasional hot spot. Small ash eruptions began again on 28 July with ash clouds again attaining altitudes of 5,500 m. By that evening, eruptions were comprised mainly of steam and the status was reduced to Yellow, although INSIVUMEH advised that the volcano had the potential for an explosive eruption with little or no warning. This situation persisted with occasional ash emissions and satellite observations of hot spots until 9 August. Activity then decreased and no explosive eruptions were detected though the evening of 11 August. As of 2 September, no additional reports regarding Fuego had been issued by NOAA's Washington Volcanic Ash Advisory Center.

Information Contacts: Otoniel Matías and Eddie Sánchez, Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, ciudad de Guatemala 01013, Guatemala; Washington Volcanic Ash Advisory Center, NOAA Satellite Services Division, NESDIS E/SP23, NOAA Science Center, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://hpssd1en.wwb.noaa.gov/SSD/ML/vaac-dc.html).

12/1999 (BGVN 24:12) 28-29 December explosions expelled ash and a 900-m-tall plume

Fuego resumed eruptive activity on 21 May 1999 (BGVN 24:04). No reports are currently available to describe August through 27 December activity.

On 28-29 December observers noted weak, moderate, and some strong explosions that emitted gray ash 100-800 m S and SW of the vent. By the evening of 28 December it was possible to observe incandescent material over the crater. The rising ash formed a black column to 300-500 m altitude, blowing S. Until 1040, seismic data revealed 22 explosions, many of moderate amplitude.

Ash expulsions continued with associated earthquakes until 0915 the following day. Later in the reporting interval, the eruptive and associated seismic activity decreased with the exception of ~35 minutes on 28 December, when a black column of ash (blowing SW) continued to escape. Consistent explosions gave off gray ash in weak-to-moderate plumes; these reached up to ~900 m over the crater. Wind carried portions of the ash plume to the E, S, and SW. When strong, the explosions were audible in nearby villages such as El Parcelamiento Morelia and Aldea Panimanche. Volcano watchers chiefly saw explosions at night, when incandescent material rose over the crater.

General Reference. Chesner, C.A., and Rose, W.I., 1984, Geochemistry and evolution of the Fuego Volcanic Complex, Guatemala: JVGR, v. 21, p. 25-44.

Information Contacts: Eddie Sánchez and Otoniel Matías, Instituto Nacional de Sismología, Vulcanología, Meteorología e Hydrología (INSIVUMEH), Ministerio de Communicaciones, Transporte y Obras Publicas, 7A Avenida 14-57, Zona 13, Guatemala City, Guatemala.

01/2000 (BGVN 25:01) Satellite data reveals hot spot; field observers see January-February ash puffs

Between 19 and 27 January, Fuego emitted ash plumes at frequencies which varied from less than 1 per hour to over 12 per hour. During 19 January, Fuego erupted at-least 28 times sending ash clouds to a height of ~ 600 m. These rates are higher than Fuego's typical eruption rate). Again on 24 and 25 January, small (~ 600 m high) ash clouds rose from the summit crater at a similar rate. On 26 and 27 January, when clouds did not obscure the summit, eruption rates were rather low.

Hot spots were apparent on GOES images (http://hotspot.higp.hawaii.edu/) throughout January while analysis of a Landsat 7 Enhanced Thematic Mapper scene acquired at 1030 on the morning of 23 January showed an intense thermal anomaly focused at Fuego's summit, a point source 120-150 m in diameter.

The recent activity resembles that observed in the February 1978 - May 1979 period, suggesting an open vent (Smithsonian Institution/SEAN, 1989).

More recently, on 12 February 2000, Steve and Donna O'Meara counted over 19 eruptions during periods when the volcano was visible. The volcano sent out ash puffs and moderately strong columns every 5 to 15 minutes. They reported further that they saw additional eruptions on 17 and 18 February before they departed the country.

Reference. Smithsonian Institution/SEAN, 1989, Global Volcanism 1975-1985: Prentice-Hall, Englewood Cliffs, NJ and American Geophysical Union, Washington, DC, 657 p.

Information Contacts: Andy Harris and Luke Flynn, HIGP/SOEST, University of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (Email: harris@pgd.hawaii.edu and flynn@pgd.hawaii.edu, URL: http://hotspot.higp.hawaii.edu/); Otoniel Matías, INSIVUMEH, 7a Av. 14-57, Zona 13, Guatemala City, Guatemala; Bill Rose, Department of Geological Engineering and Sciences, Michigan Technological University, Houghton, MI 49931, USA (Email: raman@mtu.edu); James Vallance, Department of Civil Engineering and Applied Mechanics, McGill University, Montreal, Quebec H3A 2K6, Canada (Email: james@fuego.civil.mcgill.ca); Stephen and Donna O'Meara, Volcano Watch International/Nature Stock, P. O. Box 218, Volcano, HI 96785 (Email: someara@interpac.net).

08/2001 (BGVN 26:08) Seismic activity during April and December, eruption in September 2000

Ash venting began at Fuego on 5 April 2000, followed by increased ash emissions and strong seismic signals during 7 and 8 April, according to the Guatemala Volcano Observatory and the Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH) of Guatemala. On 8 April at 0215 a hot spot was visible in multi-spectral imagery. More hot spots were occasionally noted but there were no further reports of ash.

A news article from La Hora reported that a column of ash reached 1 km on 29 August 2000. According to the Guatemala Volcano Observatory, an eruption beginning on 6 September emitted an ash-and-steam plume that reached ~800 m. On 21 September a large amount of ash was emitted, blanketing nearby communities. Authorities considered evacuating residents and issued an Orange Alert for the area near the volcano.

Satellite imagery on 7 December showed an ash plume to the SW of the summit, extending 39 km and 11 km wide. According to ground observations the ash was centered at ~4.9 km elevation. INSIVUMEH reported that the volcano was producing loud rumbling sounds and a more significant eruption was likely. On 9 December 2000 satellite imagery confirmed a small eruption at about 1645. The eruption sent an ash cloud to ~4.5 km altitude, near the summit level. The ash cloud was initially dense, about 8 km wide, and drifted W and NW. By 2345, the cloud had dissipated and was no longer visible on satellite imagery. Occasional strong hot spots were visible on GOES-8 multi-spectral imagery throughout the day. That evening, volcanologists in Guatemala indicated that the volcano had become increasingly unstable with several explosions occurring within a few hours. Since then, no major activity has occurred.

Information Contacts: Otoniel Matías and Eddie Sánchez, Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (http://www.insivumeh.pagina.de); Washington Volcanic Ash Advisory Center, NOAA Satellite Services Division, NESDIS E/SP23, NOAA Science Center, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://hpssd1en.wwb.noaa.gov/SSD/ML/vaac-dc.html); La Hora (http://www.lahora.com.gt/).

03/2002 (BGVN 27:03) Costly 1999 aircraft-ash encounters due to ash plumes

At least two commercial aircraft flew through airborne ash near the Guatemala City airport on 21 May 1999. An eruption from Fuego that day was the first at that volcano since 1987 (BGVN 24:04). Although the aviator's reports attributed the ash from this encounter to Fuego, their aircraft intersected multiple ash plumes in widely different locations, and thus they may also have crossed plumes from Pacaya. The most likely plume near the southern approach to the airport (La Aurora, ~23 km N of Pacaya; ~40 km NE of Fuego) is from the almost constantly active Pacaya. In contrast, Fuego lies 32 km W of Pacaya and was the likely source of a plume intersected later during the flight, at higher altitude, and for much longer duration.

During the encounters the ~100 or more people on board the two aircraft, and many more on the ground, were at risk. Both encounters seriously damaged the aircraft but ended in safe landings without reported injuries. Volcanic ash can cause jet-engine failure, which creates a hazard not only to passengers, but to people on the ground as well. The risk in this situation was amplified by the airport's proximity to urban Guatemala City (population, >1.1 million).

This example leads to two conclusions discussed further below. First, ash avoidance methodology needs further refinement. Second, there exists an apparent bias towards under-reporting of aircraft-ash encounters, which could short-change their cost to air carriers, their perceived risk, and their funding allocation.

The original report of an aircraft-ash encounter was brought to our attention by Captain Edward Miller of the Air Line Pilots Association and provided on the condition that the air carrier remain anonymous. Bulletin editors also wish to acknowledge conversations with several additional anonymous contacts (commercial pilots). This case occurred in Guatemala; however, analogous situations exist at many airports adjacent to volcanoes. Modest eruptions from nearby volcanoes may be uncertain or difficult to see; they may be hard to detect or characterize; yet they still may yield mobile ash plumes carried by complex local winds to confront air traffic (Salinas, 2001; Hefter, 1998; Casadevall, 1994).

Although in most Bulletin reports we favor the use of local time to emphasize the reference frame of people on the scene, most of the source material (satellite and aviation) for this report refer to UTC (Coordinated Universal Time). UTC is the time on the Greenwich meridian (longitude zero), formerly GMT, a term which has fallen out of use. Accordingly, there are cases in this report that lack conversion to local time. Local time in Guatemala is 6 hours behind UTC.

Activity at Fuego and Pacaya. Fuego erupted on 21 May 1999 sending ash to the S, SE, and SW and ultimately dropping up to 40 cm of ash on local settlements (BGVN 24:04). The eruption occurred at 1800 local time (in terms of UTC, at 0000 the next day). Three hours later the eruption decreased and the Aeronautica Civil recommended that planes go no closer to Fuego than 40 km. One hour after that (at 2200 local, 0400 UTC), the atmospheric ash had settled, and Aeronautica Civil recommended flying no closer to Fuego than 15 km.

Bulletin reports for Pacaya in mid-1999 suggested relative calm, in harmony with the observation that it had chiefly been fuming. However, Pacaya is well-known for Strombolian outbursts. It lies directly in-line and only 23 km S of the N10°E-oriented airstrip. As is common for commercial aircraft there, the approaches described below passed very close to Pacaya. Pacaya typically has lower and smaller eruptions than Fuego, but because it lies so close to the southern approach to the airport, Pacaya's ash plumes easily enter the path of landing aircraft. The situation was particularly complex during this eruption because Fuego's ash was reported on cities that lie below the flight path as well as on the Pacaya's flanks.

Pilot's report of aircraft-ash encounter. What follows was taken from one flight crew's description of events and from later reports and dialog on the topic. In order to preserve the confidentiality of the airlines, the precise times of events on 21 May 1999 have been omitted. Pilots reported clear visibility and light wind, with both the capital and the airport in sight. They maneuvered the aircraft for a final approach from the S. Pilots were advised by air traffic control about erupted particulate ("volcanic sand") about 24 km (15 miles) SE of the airport, well away from their projected path to Runway 01. In addition, based on winds they detected as they neared the airport, the pilots concluded that the erupted particulate to the SE was downwind from their projected flight path to the airport. (In retrospect, this conclusion appears tenuous considering the possibility of either a fresh injection of ash from Fuego, or lingering ash in the trailing portion of the plume that lay to the SE.)

At ~32 km (20 miles) distance from the runway, the pilots maneuvered the plane through ~3,000 m (9,700 feet) altitude on a final approach to the airport with the plane's flaps partially extended (at ~15°, which slowed their aircraft to ~260 km/hour (160 mph), its auxiliary power unit (a small jet engine) on, and its landing gear down. Around this point in their descent, pilots saw bright yellow sparks through the windshield lasting a few seconds, a display unlike static electricity, but rather like that from a grinding wheel. This occurred again at 2,500 m (8,200 feet) altitude, but was more intense yet intermittent.

At this time, air-traffic control announced to the pilots that the aircraft landing in front of them had encountered volcanic particulate; they instructed the pilots to abort their landing and climb to 3,350 m (11,000 feet) altitude. Discussions of options and ash avoidance ensued between pilots and air-traffic control; ash had by this time accumulated on the runway, further complicating landing, even for approaches in the opposite direction. The pilots retracted the landing gear, accelerated to ~410 km/hour (~250 mph), began to climb, and after some discussion with air-traffic control, held on a course NE of the airport. They were subsequently cleared to climb to 6,700 m (22,000 feet) altitude and advised to proceed to an alternate airfield.

During the climb, at ~5,800 m (19,000 feet) altitude en-route to the alternate airport, the aircraft encountered volcanic particulate for 10 minutes. Within that interval the plane spent 2 minutes during ascent engulfed in denser and heavier particulate. During that period, window arcing was constant and the beam of their landing lights revealed a conspicuous cloud of reflecting particles. During ash ingestion the engines's speed lacked noticeable fluctuations. The aircraft exited the plume at about 6,100 m (20,000 feet) altitude and landed without encountering additional ash.

Upon landing, the pilots noticed reduced visibility through abraded windshields. Post-flight examination of the airplane revealed heavy damage, requiring the replacement of the engines (US $2 million each) and auxiliary-power-unit engine. (Note, however, that no deterioration in engine power or performance was noticed during the flight.) Other replaced parts included windshields, a heat exchanger, and coalescer bags. Minor damage was seen on the horizontal stabilizer and wing leading-edges.

Volcanic Ash Advisory Statements. The U.S. National Oceanic and Atmospheric Administration (NOAA), Satellite Services Division website contains two archived statements issued by the Volcanic Ash Advisory Center (VAAC) at Washington, D.C. for Fuego on 21-22 May 1999. The statements, issued to the aviation cummunity to warn of volcanic hazards, are intended for an audience accustomed to special terminology (figures 2 and 3). In the interest of advancing understanding of how volcanological and atmospheric data get transmitted to aviators, we offer brief explanations for many of the terms used (figure 2).

Figure 2. The first archived Volcanic Ash Advisory Statement (VAAS) for the 21 May 1999 eruption at Fuego, Guatemala. The boxes contain added notes to explain some of the basic conventions and specific details seen here. This Statement currently appears on the NOAA Satellite Services Division website (see "Information Contacts," below). Local names are frequently anglicized, dropping all accents and other non-English characters (eg. México would be written MEXICO). Later Advisories adopted the abbreviation "Z" (pronounced 'Zulu' by aviators) for UTC, as in 1300 UTC written as 1300Z.
Figure 3. A later Volcanic Ash Advisory Statement (VAAS) for the 21 May 1999 eruption at Fuego, Guatemala. The statement, which was issued the next day, discloses that the eruption had then stopped and the hazard status was lowered. The statement appears on the NOAA Satellite Services Division website (see "Information Contacts," below).

The Washington VAAC received first notification of the Fuego eruption from a routine surface weather observation from Guatemala City at 2000 local time (0200 UTC) on 22 May. They issued the first Volcanic Ash Advisory Statement a half-hour later (figure 2). Six hours later they issued the second Advisory Statement (figure 3). The Advisories were composed by staff of the Satellite Analysis Branch, one of the two NOAA components forming the Washington VAAC (Streett, 1999; Washington VAAC).

The section "Details of ash cloud" first says that the "surface observation from Guatemala City indicate that the Fuego volcano is in eruption" and that no additional information is available and then briefly describes in words observations that came from satellite imagery. The first sentence, "No eruption . . ." is self-explanatory, but highlights a limitation of the method in use that needs to be emphasized to aviators: an eruption may have occurred but its status is not revealed on the imagery. The sentence, "No eruption could be detected due to thunderstorm cloudiness covering the area around the volcano" is self-explanatory. Less clear is the term convective debris. It does not refer to ash; rather, it refers to remnants of thunderstorms. The gist of these latter two sentences is simply that the thunderstorms that covered the area made it challenging or impossible to see the ash on satellite imagery. Central American thunderstorm clouds typically can reach altitudes of more than 12,000 m (40,000 feet), and can mask or obscure airborne ash residing below that level.

Members of the Washington VAAC commented that this eruption demonstrates key problems that can arise when cloudy conditions prevent satellite detection of ash, foiling a primary mode of analysis. In such cases, they rely on ground observers (including observatories and weather observers), pilot reports, and reports from airlines. Thus, their ability to issue useful information in cloudy conditions depends on the quality of communications with local observers, the Meteorological Watch Office, volcanologists, geophysical observatories, and the aviation community.

The Advisory Statement listed México City weather balloon data acquired 1,050 km NW of Guatemala City. In retrospect, the Washington VAAC noted that they generally avoid using such distant sounding data. If a closer sounding cannot be found, they prefer to use upper-level wind forecasts taken from a numerical weather model. In any case, the scarcity of local sounding data presents a challenge to the realistic analysis of airborne ash.

The outlook section says to "see SIGMETS." SIGMETS are the true warnings to aircraft for SIGnificant METeorological events. They are issued by regional Meteorological Watch Offices (MWOs), in this case the MWO (for Guatemala) is in Tegucigalpa, Honduras. SIGMETS were lacking for this eruption; although the Washington VAAC tried to contact the MWO without response. Another complexity confronted at the VAAC is a lack of a single scale for communicating a volcano's hazard status.

Reporting of aviation ash encounters. In personal communications with Bulletin editors, airline personnel stated that many more encounters have occurred than have yet been tallied in publically accessible literature. In accord with those assertions, the 21 May 1999 encounters are absent from reports compiled by the International Civil Aviation Organization (ICAO, 2001). In that document (Appendix I, table 3A, p. I-12) Fuego fails to appear as a source vent for any aircraft-ash encounter. Pacaya is listed for two encounters, in January 1987 and in May 1998 (BGVN 23:05).

Even though the number of encounters was probably under-represented and thus reflects a minimum, ICAO (2001) notes that the international costs to aviation since 1982 summed to well in excess of $250 million. They noted, "In addition to its potential to cause a major aircraft accident, the economic cost of volcanic ash to international civil aviation is staggering. This involves numerous complete engine changes, engine overhauls, airframe refurbishing . . . aircraft downtime . . . [and] volcanic ash clearance from airports and the damage caused to equipment and buildings on the ground."

The incidents here suggest that there has been a strong bias toward under-reporting aircraft-ash encounters. If this tentative conclusion is correct, it implies consistent understatements of the hazard's magnitude. This, in turn, may have thwarted meaningful analysis of how and whether to proceed with designing more robust hazard-reduction systems. Accordingly, resources that could have been devoted to the problem have not yet been committed (see Gimmestad and others, 2001 for a discussion of a prototype on-board ash-detection instrument).

Communication challenges. While much of the aviation community needs to learn about volcanism rapidly, dependably, and with the aid of the Internet, some observers charged with reporting volcanic-ash hazards in Central and South America lack access to basic communication devices like reliable telephones and fax machines. To reduce the risks, the aviation, meteorological, remote sensing, and volcanological communities need to improve their ability to pass critical information to each other rapidly and precisely. The operational systems related to volcanic ash and aviation must transcend numerous boundaries (eg., languages, infrastructure, funding, governments, agencies, air carriers, pilots, aircraft manufactures, etc.). The systems need to portray complex, dynamic processes such as the rapid rise of an explosive plume, or large-scale ash-cloud movement.

Although the infrastructure for ash avoidance is greater than ever, members of the Washington VAAC have told Bulletin editors that they still depend heavily on people on the scene of the eruption to notify them promptly when eruptions occur. They said that thus far in parts of Central and South America a problem has been the expense of communication (eg., by phone, fax, and Internet). They also said that for the same regions the U.S. meteorological database regularly lacks pilot reports. Though serious, these problems have at least been identified and their solutions would appear to lack great technical or economic barriers.

The pilots involved in the May 1999 encounter recommended that far more emphasis be placed on forecasting and avoiding ash plumes. Other pilots cited the need for fast and accurate communications between those who observe eruptive activity and air traffic control personnel.

Issues like these continue to be an important subject at gatherings on the topic of ash hazards in aviation (Casadevall, 1994; Streett, D., 1999; Washington VAAC, 1999). The Airline Dispatcher's Federation (ADF) will participate in a 7-9 May 2002 conference and workshop: "Operational Implications of Airborne Volcanic Ash: Detection, Avoidance, and Mitigation." The gathering will provide the pilot and dispatcher with insights into volcanic ash, including its characteristics, affects on aircraft, detection/tracking, effective warning systems, and mitigation. A "hands-on" exercise will make this the first gathering of its kind to provide lab-style instruction on interpretation of satellite and wind data, and on models of ash trajectory and dispersion. Representatives from the Boeing company, and a host of US government agencies and non-governmental organizations will attend. The workshop will include lectures, demonstrations, laboratory exercises, and a simulated-eruption exercise involving volcanologists, forecasters, controllers, dispatchers, and pilots.

A second international symposium on ash and aviation safety is being planned by the U.S. Geological Survey, organized by Marianne Guffanti. It will be held in Washington, D.C. in September 2003.

References. Casadevall, T.J. (ed.), 1994, Proceedings of the First International Symposium on Volcanic Ash and Aviation Safety: U.S. Geological Survey Bulletin 2047, 450 p.

Gimmestad, G.G., Papanicolopoulos, C.D., Richards, M.A., Sherman, D.L., and West, L.L., 2001, Feasibility study of radiometry for airborne detection of aviation hazards, NASA/CR-2001-210855; Georgia Tech Research Institute, Atlanta, Georgia, 51 p. (URL: http://techreports.larc.nasa.gov/ltrs/PDF/2001/cr/).

Hefter, J.L., 1998, Verifying a volcanic ash forecasting model, Airline Pilot, v. 67, no. 5, pp. 20-23, 54.

International Civil Aviation Organization (ICAO), 2001, Manual on volcanic ash, radioactive material, and toxic chemical clouds, doc 9691-AN/954 (first edition): 999 University St., Montreal, Quebec, Canada H3C 5H7 (purchasing information: sales_unit@icao.int).

Rose, W.I., Bluth, J.S.G., Schneider, D.L., Ernst, G.G.J., Riley, C.M., Henderson, L.J., and McGimsey, R.G., 2001, Observations of volcanic clouds in the first few days of atmospheric residence: The 1992 eruptions of Crater Peak, Mount Spurr volcano, Alaska, Jour. of Geology, v. 109, p. 677-694.

Salinas, Leonard J., 2001, Volcanic ash clouds pose a real threat to aircraft safety: United Airlines, Chicago, Illinois (URL: http://www.dispatcher.org/library/VolcanicAsh.htm).

Simkin, T., and Siebert, L., 1994, Volcanoes of the World, 2nd edition: Geoscience Press in association with the Smithsonian Institution Global Volcanism Program, Tucson AZ, 368 p.

Streett, D., 1999, Satellite-based Volcanic Ash Advisories and an Ash Trajectory Model from the Washington VAAC: Eighth Conference on Aviation, Range, and Aerospace Meteorology, 10-15 January 1999, Dallas, Texas; American Meteorological Society, p. 290-294.

Washington VAAC, 1999, Operations of the Washington Volcanic Ash Advisory Center, in Aeronautical meteorological offices and their functions, and meteorological observation networks: Third Caribbean/South American Regional Air Navigation Meeting (Car/sam/ran/3); Buenos Aires, Argentina, 5 - 15 October, 1999; International Civil Aviation Organization (http://www.ssd.noaa.gov/ VAAC/PAPERS/carsam.html).

Information Contacts: Captain Edward Miller, Air Line Pilots Association (ALPA), Air Safety & Engineering Department, 535 Herndon Parkway, PO Box 1169, Herndon, VA 22070-1169, USA; Grace Swanson and Davida Streett, Washington VAAC, Satellite Analysis Branch (NOAA/NESDIS), 4700 Silver Hill Road, Stop 9910, Washington, DC 20233-9910, USA (URL: http://www.ssd. noaa.gov/, Email: Grace.Swanson@noaa.gov, dstreett@ssdnotes.wwb.noaa.gov); Bill Rose, Geological Engineering and Sciences, Michigan Technological University, Houghton, MI 49931, USA (Email: raman@mtu.edu).

08/2002 (BGVN 27:08) Explosions, ash emission, and lava flows during January-February and July 2002

On 4 January 2002, an eruption began at Fuego during 0200-0300. A probable explosion was followed by Strombolian-type ejections and continuous tremor, but no lava flows were visible. Intermittent mild-to-moderate explosions continued during the next few days, producing ash clouds that rose 400-600 m.

In late January, Fuego continued to erupt a lava flow down its E flank. The flow stretched several hundred meters below the summit before falling apart on steep slopes. The toe of the flow calved off about once a minute, but the volume of material was not sufficient to generate pyroclastic flows. Minor amounts of ash were kicked up when the front flow calved. Incandescence from the flow front was visible from Antigua. No explosive activity was observed and only low-level tremor was recorded. A generally white plume was observed.

Based on information provided by Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), the Washington VAAC reported that on 1 February at 0930 ash, steam, and lava were emitted from Fuego. An ash-and-steam cloud rose to ~4.5 km altitude and drifted to the SW. No ash was seen on satellite imagery, but a hotspot was visible on infrared imagery. News reports stated that as of 10 February the increase in earthquakes and gas emissions at Fuego led Coordinadora Nacional para la Reducción de Desastres (CONRED) to declare Alert Level Yellow for the departments of Chimaltenango, Sacatepéquez, and Escuintla. On 10 February INSIVUMEH reported that more than 400 explosions occurred at Fuego in comparison to the ~75 daily explosions that had normally occured in the recent past. During the evening, incandescent lava was seen flowing down the volcano's S flank.

Volcanism increased at Fuego on 12 February, with a ~2-km-long lava flow streaming down its flank towards an unpopulated area. Several shelters were set up in the event that the lava flows traveled towards populated areas or if volcanism increased.

A new cycle of eruptive activity began at Fuego on 16 July that consisted of an increase in Strombolian explosions and the occurrence of high-frequency volcanic tremor for 24 hours. On 28 July a thick gray ash cloud drifted 10-15 km to the W. Ash was deposited in the areas of Rochela, Panimaché, Morelia, Santa Sofía, and to the W in Yepocàpa, Chimaltenango. This activity was associated with a collapse of the front of the lava flow in the Las Lajas drainage, which began on 23 January.

On the evening of 29 July the FG3 station registered an increase in seismicity (particularly in continuous tremor) during a 24-hour period. The intensity of the explosions in the crater also increased, and the lava flow reached 2-3 km in length. Early on 2 August the explosions became more vigorous, changed from Strombolian to Vulcanian, and ash columns rose 800-1,400 m above the crater. A column of fine ash extended 4 km W.

Beginning on 2 August, the emanation of gases from the crater diminished considerably, and the SE lava flow decreased in length. COSPEC measurements on the same day revealed that SO2 was at moderate levels (394 metric tons), and had increased since measurements taken on 18 June (319 metric tons) (table 1). RSAM data showed an increase in activity during 26 July-3 August, when values peaked at ~675 RSAM units. After 3 August, RSAM values gradually decreased, reaching a value of ~375 RSAM units by 9 August. In the villages of Panimaché (4 km SW) and Zapote (SE flank) a decrease in water levels coincided with increased fumarole activity and frequency of volcanic tremor.

Table 1. SO2 fluxes at Fuego during January-August 2002. Courtesy Lizzette A. Rodriguez, William Rose, Matthew Watson, Yvonne Branan, Gregg Bluth (MTU), Simon Carn (University of Maryland Baltimore County), and Gustavo Chigna and Otoniel Matías (INSIVUMEH).

    Date          SO2 emission
                 rate (tons/day)

    07 Jan 2002      223.5
    14 Jan 2002      330.2
    02 Feb 2002      248.7
    15 Feb 2002      364.9
    19 Feb 2002      356.4
    01 Mar 2002      512.4
    06 Mar 2002      652.6
    22 Mar 2002      823.0
    17 Apr 2002      464.9
    19 Apr 2002      587.9
    18 Jun 2002      318.5
    02 Aug 2002      394.0
    20 Aug 2002      216.1

"Kiwi" Bhatia reported that Fuego erupted almost continuously during 17-23 July. He estimated that the lava flow advanced 30 m or more. Pyroclasts tumbled down the flanks. Strong rumblings during 10-21 August were loud enough to be heard from neighboring farms.

According to Glyn Williams-Jones (HIGP/SOEST), GOES hot-spot monitoring may indicate a potential cyclical nature to thermal activity observed at the volcano. In order to facilitate and automate GOES monitoring, a new comparison technique developed by Wright and others (in review) is being tested. A correlation term (R2) compares the peak radiance of a given pixel with the mean background radiance. Changes in activity can be recognized due to their sudden lack of correlation. This technique can be illustrated by the poor correlation (R2 significantly less than 0.9) for the 28 July and 2 August ash emissions (figure 4). From August 19 onwards, activity appears to have returned to "background" levels (i.e., R2 greater than 0.9).

Figure 4. A plot showing R-squared correlation values (y-axis) versus date (x-axis) at Fuego during January through mid-August 2002. The correlation values (R2) compare band 2 peak vs. mean pixel radiance. Perfect correlation (R2 = 1.0) suggests non-eruptive conditions, decreased correlation (R2 significantly less than 0.9) suggests possible eruptions. In other words, the peaks on this plot suggest eruptive conditions. Courtesy HIGP/SOEST.

Jacquelyn Gluck reported that visual observation during the afternoon of 25 August and at night on 26 August revealed no activity. No incandescence was seen by observers on high points in Antigua looking to the SW.

Reference. Wright, R., Flynn, L.P., Garbeil, H., Harris, A.J.L., and Pilger, E., 2002, MODVOLC: near-real-time thermal monitoring of global volcanism: JVGR, in review.

General Reference. Chesner, C.A. and Rose, W.I., 1984, Geochemistry and Evolution of the Fuego Volcanic Complex, Guatemala; JVGR, v. 21, p. 25-44.

Information Contacts: Gustavo Chigna M. and Otoniel Matías, Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Juan Pablo Ligorria, Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (Email: jligorria@conred.org.gt); William Rose, Matt Watson, Yvonne Branan, Lizzette Rodríguez, and Gregg Bluth, Michigan Technological University, Houghton, MI 49931, USA; Glyn Williams-Jones, HIGP/SOEST, University of Hawaii at Manoa,1680 East-West Road, Post 602, Honolulu, HI 96822, USA (Email: glynwj@higp.hawaii.edu); Simon Carn, TOMS Volcanic Emissions Group, Joint Center for Earth Systems Technology (NASA/UMBC), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA (Email: scarn@umbc.edu); John W. Ewert and Randy White, U.S. Geological Survey, Volcano Disaster Assistance Program, 5400 MacArthur Blvd., Vancouver, WA 98661, USA (URL: http://volcanoes.usgs.gov/, Email: jwewert@usgs.gov, rwhite@usgs.gov); Washington Volcanic Ash Advisory Center, NOAA Satellite Services Division, NESDIS E/SP23, NOAA Science Center, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://hpssd1en.wwb.noaa.gov/SSD/ML/vaac-dc.html); United Nations Office for the Coordination of Humanitarian Affairs (OCHA), United Nations, New York, NY 10017, USA (URL: http://www.reliefweb.int); Jim Vallance, McGill University, Department of Civil Engineering & Applied Mathematics, 817 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada; Rafael W. Rodriguez, U.S. Geological Survey, c/o American Embassy, Avenida Reforma 7-01 Zona 10, Ciudad Guatemala 01010, Guatemala (Email: rrodrigu@usgs.gov).; D.M.S. Bhatia, Department of Geology, Austin Peay State University, Clarksville, TN 37044, USA (Email: bhatiad@apsu.edu); Jacquelyn Gluck, Global Volcanism Program, Smithsonian Institution, Washington, DC 20560-0119, USA; The Clinton Courier, Prensa Libre, Associated Press.

01/2003 (BGVN 28:01) Explosive eruptions from September 2002 through January 2003

Explosions, ash emission, and lava flows took place during January-February and July 2002 (BGVN 27:08). MODIS thermal alerts were recorded monthly throughout 2002. CONRED reported that during the last 3 months of 2002, a change in behavior at Fuego was characterized by an increase in Strombolian activity. Ash emission and pyroclastic flows threatened communities to the SW, which prepared for evacuation (figure 5). This report covers the period of 26 December 2002 through mid-January 2003.

Figure 5. This condensed-format map of Fuego hazards was intended as a poster when created by the Guatemalan agency CONRED. North is towards the top; the original map key and credits are truncated from this version. The map shows six different hazard zones with a gradation of expected hazards, as well as some of the critical close-in population centers and their suggested departure routes. The large population center Antigua lies off the map, 17 km NE of Fuego's summit. Courtesy of CONRED.

According to news reports, an explosive eruption and partial crater collapse occurred on 26 December 2002 around 0905. An ash cloud was generated that reached ~2 km above the volcano and drifted W toward the Yepocapa region. Neither damage nor injuries were reported.

The Washington VAAC reported that an eruption began at Fuego on 8 January 2003 around 0500. According to INSIVUMEH, as of 1100 that day the eruption continued with ash explosions and lava flow emission. A steam-and-ash column rose to 5.7 km altitude and drifted to the W. In addition, two small-to-moderate pyroclastic flows traveled down the Santa Teresa river valley. Seismic signals continued to show evidence of magma ascent, but fewer in number with 15-25 explosions per minute recorded. This suggested continued effusive emissions for a number of hours. During the eruption, ash fell in an elliptical area chiefly W of Fuego; other events included rumbling, and fumarolic activity. CONRED stated that the Alert Level was raised to Orange and several people were evacuated from the town of Sangre de Cristo. According to a news report volcanism decreased the following day, so the Alert Level was lowered from Orange to Yellow.

INSIVUMEH reported that as of 19 January moderate eruptions continued at Fuego that produced ash clouds to 1.5-3 km altitude. Ash drifted to the S and SW, depositing fine ash in the areas of Rocela, Panimache, and Palo Verde. In addition, incandescent avalanches traveled down canyons on the volcano's flanks. Table 2 shows ash advisories issued for Fuego by the Washington VAAC during January.

Table 2. Volcanic ash advisories issued for Fuego during January 2003. Courtesy Washington VAAC.

     Date     Time    Observation
    (2003)    (UTC)

    08 Jan    1640    Satellite imagery showed a vivid hot spot. A
                        possible ash plume was observed moving W from
                        the summit at 1545Z. By 1615Z the narrow plume
                        extended ~18 km to the W of the summit.
    08 Jan    2010    Satellite imagery through 1945Z showed a larger
                        eruption occurring with ash estimated to FL200
                        (6 km). The bulk of the ash was moving N but
                        some moved W. The initial ash plume had detached
                        and was moving W toward the coast.
    09 Jan    0200    Ash was not visible in nighttime infrared or
                        multispectral imagery. The last visible image of
                        the day showed ash to the W and NW of the summit
                        moving at 18-28 km/hour. Guatemala City airport
                        reported continuing eruptions.
    09 Jan    0755    Ash was not visible in infrared of multispectral
                        imagery through 0715Z. Imagery showed a strong
                        and persistent hot spot. Guatemala City airport
                        reported continuous eruptions.
    09 Jan    1400    Ash was not visible in infrared or multispectral
                        imagery through 1315Z. A persistent strong hot
                        spot continued in shortwave imagery.
    09 Jan    1915    Ash too thin to be detected in satellite imagery.
                        An occasional hot spot was detected in short
                        wave imagery.
    11 Jan    1610    Thin faint ash plume seen in satellite imagery
                        extending W from the volcano ~83 km.
    11 Jan    2150    Ash not identifiable in satellite imagery. Surface
                        reports from Guatemala city through 2100Z
                        continued to indicate that the volcano was
                        active. A hot spot continued to be observed in
                        satellite imagery.
    12 Jan    0400    Ash not identifiable in satellite imagery. No
                        further reports from Guatemala. Hot spot
                        continued to be observed in satellite imagery.
    12 Jan    1030    Ash not identifiable in satellite imagery. Surface
                        reports from Guatemala City indicated that Fuego
                        was active. An intermittent hot spot was seen in
                        satellite imagery.
    12 Jan    1615    Ash not identified in satellite imagery and no
                        hotspot was seen at the summit. Surface reports
                        indicated continuing activity.
    20 Jan    0430    A report from the Guatemala Volcano Institute
                        indicated that ongoing activity produced an ash
                        cloud to 2 km above the summit (~5.8 km
                        altitude) moving S and SW. Multi-spectral
                        imagery showed the ash in a 18-km-wide line
                        extending ~33 km  from the summit. The report
                        also indicated that ash was falling in the areas
                        of La Rochela, Panimache, and Palo Verde.
    20 Jan    1030    Ash plume became diffuse and difficult to see on
                        multi-spectral imagery. Around 530Z another puff
                        of ash was seen moving to the SW and an
                        intermittent hotspot was visible for the past
                        few hours
    20 Jan    1630    Exhalation of ash and steam at 0615Z. Ash plume
                        diffuse and difficult to see on satellite
                        imagery.

Observations during 3-13 January 2003. Craig Chesner and Sid Halsor reported continuous low-level volcanic activity and one larger event at Fuego during a 10-day site visit. Nearly continuous Strombolian-type spattering and fountaining were observed during the night of 3 January. Bombs and blocks, ejected up to several tens of meters above the summit vent, fell on the upper flanks. No ash was observed during this activity, although ashy trails were generated from ejecta tumbling down the steep southern and eastern slopes of the volcano. On 4 January, no lava fountaining was observed, and activity was characterized by steady and passive emission of a gas plume.

Energetic fountaining and spattering were observed during the night of 5 January from a vantage point on the summit of nearby Agua volcano. Fourteen Strombolian explosions occurred at intervals of 5-61 minutes during 5 hours of continuous observation. These explosions ejected incandescent material ~100 m above the cone, showering the upper flanks with blocks and bombs. Typically, each explosion was accompanied by a loud detonation and an ash plume, and led to several minutes of vigorous fountaining. This activity continued during the morning of 6 January, but by evening, no incandescent activity was apparent at the summit vent.

On the morning of 7 January, a new lava flow was noted on the southern flank, and ash trails generated from spalling blocks suggested that it was active. In the evening, vigorous lava fountaining and spattering had resumed, and the lava flow was seen descending from the summit area to the S. A nearly continuous cascade of pyroclasts produced incandescent rock falls on the upper flanks of the cone.

At 1030 on 8 January, an expansive plume of ash had developed over the summit area. Concurrent fountaining and pulsating eruptions of ash were observed from a vantage point near Alotenango, a few kilometers NE of the volcano. By 1100, the eruption column was broadening at its base, darkening in color, and extending to considerable height above the summit. The most intense phase of the eruption occurred roughly between 1145 and 1215 (figure 6). During this time, loud rumbling and swashing-like sounds accompanied continuous fountaining and frequent, energetic eruptions of ash. A bright incandescent fire fountain, several tens of meters high, was clearly observed at the base of the ash column. Twice during this time period, lateral ash columns, presumably associated with pyroclastic flows, were noted descending towards the W. A convective column engulfed the summit area and appeared to rise several kilometers to an altitude of ~2-3 times the height of the cone.

Figure 6. Image of Fuego eruption taken on 8 January around 1200. View looking W from about 10 km away. The eruption cloud was dispersed westward and the ground-hugging smaller cloud just W from the summit area may have been associated with reported pyroclastic flows. Courtesy Sid Halsor.

By 1245, eruptive activity appeared to subside with eruptions becoming less frequent and gradual lightening in color of the ash cloud. Throughout the afternoon, the ash cloud drifted westward and dispersed ash-laden air over a broad region. A circumnavigation of the volcano during the afternoon indicated no detectable ash fall along the dispersal axis at a distance of ~9 km. However, a slight discoloration of vegetation was noted to the E of Yepocapa. Intermittent low to moderate ash eruptions continued throughout the day and summit fountaining was observed at night. The following morning (9 January), no visible activity was noted over a brief observational period. However, the summit area surrounding the vent had clearly changed, being asymmetrically higher to the NW. From 10-13 January, activity was characterized by periodic low-level Strombolian explosions and associated ash plumes. These plumes could be seen from as far away as western El Salvador.

Information Contacts: Gustavo Chigna M. and Otoniel Matías, Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Juan Pablo Ligorria, Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (Email: jligorria@conred.org.gt); Washington Volcanic Ash Advisory Center, NOAA Satellite Services Division, NESDIS E/SP23, NOAA Science Center, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://hpssd1en.wwb.noaa.gov/SSD/ ML/vaac-dc.html); Craig A. Chesner, Geology/Geography Department, Eastern Illinois University, Charleston, IL 61920, USA (Email: cfcac@eiu.edu); Sid P. Halsor, GeoEnvironmental Science and Engineering, Wilkes University, Wilkes-Barre, PA 18766 (Email: shalsor@wilkes.edu); EFE via COMTEX, Prensa Libre, Siglo XXI.

10/2003 (BGVN 28:10) Explosive eruptions and lava flows through October

Explosive and effusive activity, last reported through January 2003 (BGVN 28:01) has continued through October 2003. Plumes identified on satellite imagery between April and September 2003 were described in aviation advisories issued by the Washington Volcanic Ash Advisory Center (VAAC). Regular reports of daily activity provided by the Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH) on their website have been summarized for many days in the second half of October.

Activity during April-September 2003. The Washington VAAC reported that on 28 April 2003 Fuego generated intermittent ash eruptions. One cloud was observed at ~ 7 km altitude moving SW at 19-29 km/hour. On 2 May the VAAC reported possible ash around the summit, but as of 1515, none was visible. INSIVUMEH indicated that although Fuego was active with explosions, most ash was confined to near the summit.

On 29 June INSIVUMEH reported a moderate eruption during 1745-2200 that consisted mainly of lava effusion. Lava flows were observed on the E flank, in the Lajas, Jute, and Barranca Honda ravines. Avalanches generated sounds similar to a locomotive, with strong rumblings and acoustic waves. Fuego's Observatory 2, on the SW flank, reported 2 cm of ashfall. Ashfall also occurred in San Pedro Yepocapa, Patulul Suchitepequez, Cocales, and villages W and SW of the volcano. At about 2335 there was a reduction in seismic activity at the Fuego 3 station.

INSIVUMEH reported on 1 July that explosive activity continued with weak to sometimes strong explosions ejecting grayish ash up to 900 m above the crater, with occasional degassing sounds and rumblings. Pyroclastic-flow material moved into the W-flank Seca and Santa Teresa valleys, 1.5 km from the village of Sangre de Cristo. A pyroclastic flow was reported by the Washington VAAC at 1130 on 9 July. INSIVUMEH reported strong explosions with ash to 2 km above the summit, a plume extending 5-7 km W, and ashfall to the W and SW. GOES-12 imagery showed a 3.7-km-wide plume extending ~ 11 km W.

The Washington VAAC reported on 7 August that a brief puff of ash was ejected at about 1600; the small plume moved to the NW and dissipated by 1745. On 28 September the Washington VAAC, based on visible and multi-spectral IR techniques, reported an ash eruption at about 1100. This plume, which was ~ 5 x 5 km, moved S toward the coast and was no longer discernable on imagery by 1400. A second ash emission between 1415 and 1432, with an approximate altitude of 6 km, was partially obscured by clouds.

Activity during 15-30 October 2003. On 15 October INSIVUMEH reported the continuation of eruptive activity, with degassing and small rumbling sounds. Incandescence was seen above the crater at night. The ejected ash was dispersed around the volcanic edifice. A small eruption that began at 0007 on 17 October ended at 0040 after five moderate explosive pulses, each 2-3 minutes in duration, generated thick columns of grayish ash ~ 1,500 m high. Before and after this eruptive event moderate and strong explosions caused rumbling and shock waves felt at the OVFGO and FG2 observatories. Small incandescent avalanches moved towards the Santa Teresa valley.

Harmonic tremor was registered at the FG3 station at 1630 on 20 October. On 21 October, INSIVUMEH reported explosions after 0350. The majority were strong, expelling abundant incandescent material. Ash columns caused small and moderate avalanches, mainly in the Santa Teresa and Trinidad valleys, and occasionally in the Taniluyá. Shock waves were felt by communities around the volcano. Slight ashfall occurred in the Morelia and Santa Lucia villages located 7 and 10 km, respectively, SSW of the active crater.

On 23 October, INSIVUMEH reported moderate, weak and occasionally strong explosions producing grayish and blackish plumes up to one km high. Moderate and strong explosions generated rumbling and lava flows that traveled toward the Santa Teresa and Trinidad valleys. Ashfall occurred in the upper portion of the Fuego-Acatenango complex. At 0945 a strong explosion, lasting 1.5 minutes, produced a thick ash cloud that reached a height of ~ 1 km and dispersed to the SW. Two short pulses lasting 45-60 minutes between 1200-1300 and 1800-1900 on 23 October generated a series of 7-9 moderate explosions that produced a grayish column to ~ 1 km over the central crater.

A strong explosion at 0910 on 27 October was preceded by five moderate explosions at intervals of 3-7 minutes that produced gas clouds and ash 700 m high. The first event produced a heavy ash column of a height of ~ 1 km which dispersed to the SW. An explosion at 0625 caused a pyroclastic flow toward the Trinidad and Santa Teresa valleys, and produced light ashfall in the village of Sangre de Cristo. On 29 October INSIVUMEH reported predominantly weak and moderate explosions 1-3.5 minutes long with gas-and-ash columns up to 1 km high. The last of these produced ashfall, shock waves felt at OVFGO, and avalanches of incandescent material toward the Santa Teresa and Trinidad valleys.

On 30 October an effusive eruption during 2300-0600 produced incandescent lava fountains 75-100 m high with pulses of 5-6 minutes, changing to fountains ~ 50 m high and 15-20 minutes long. A short lava flow descended SW from the crater rim, reaching ~ 250 m in length and splitting into three short branches. Short avalanches and pyroclastic flows descended to the top of the Santa Teresa valley. The eruption produced moderate to weak sounds lasting ~ 2 minutes. At dawn, a thick fumarolic plume was observed blowing NW. There was no ash emission during this activity, but at 0625 hours a small explosion sent a column of gas and ash ~ 400 m high. The seismic station at FG3 registered harmonic tremor (2-4 mm amplitude).

Information Contacts: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/).

11/2004 (BGVN 29:11) Explosions and lava flows continued in November-December 2003

Explosions and lava flows at Fuego continued after October 2003 (BGVN28:10). Similar activity prevailed through 2003 and 2004. This report discusses events during November-December 2003 and includes a table summarizing Fuego's 2003 behavior (table 3). A future report will discuss 2004 activity and will include a map showing critical place names. Several pyroclastic flows occurred in 2003.

Table 3. Representative examples of reported volcanism at Fuego during 2003. Courtesy of INSIVUMEH.

    Date            - Lava flows, incandescent avalanches, and pyroclasticflows (PFs)
                    - Ash column and ash fall
                    - Data source(s)

    08 Jan 2003     - Lava flows. Two PFs (down Sta. Teresa drainage).
                    - Steam-and-ash to ~ 5.7 km a.s.l., drifted W.
                    - INSIVUMEH, CONRED, Washington VAAC, EFE via COMTEX, Prensa Libra

    Mid Jan 2003    - Incandescent avalanches down flanking canyons.
                    - ~2 km above summit, drifting S and SW, depositing fine ash.
                    - INSIVUMEH, Washington VAAC

    28 Apr-01 May   - Incandescent avalanches.
                    - Intermittent ash eruptions, One ash plume reached ~ 7 km a.s.l., blown SW
                      at 20-30 km/hour; some puffs visible over the coast.
                    - INSIVUMEH, Washington VAAC; US Air Force Weather Agency

    29 Jun 2003     - Lava flows and avalanches down E flank (incandescence seen from city of
                      Antigua and the coast). PFs extended ~ 1.5 km down the W flank.
                    - Ash fell in villages to W and SE; Ash clouds to ~ 900 m.
                    - INSIVUMEH

    09 Jul 2003     - Lava dome collapse PFs.
                    - Strong explosions sent ash to ~ 2 km above summit; ash fell to W and SE
                      of summit.
                    - Washington VAAC, Prensa Libre

    07 Aug 2003     - N/A
                    - A small ash emission seen on satellite imagery. The ash cloud drifted NW
                      and covered an area about 3.5 by 3.5 km.
                    - Washington VAAC

    08 Sep 2003     - N/A
                    - Ash plumes; one drifted S and covered an area of 5 x 5 km; another rose
                      to ~ 6 km a.s.l.
                    - Washington VAAC

    09 Oct 2003     - N/A
                    - A pilot saw Fuego ash reaching ~ 4.6 a.s.l. No ash was visible on
                      satellite imagery.
                    - Washington VAAC

    17 Oct 2003     - Small incandescent avalanche down the Sta. Teresa valley.
                    - A 33-minute-long eruption sent a gas-and-ash plume to ~ 1.5 km above
                      the crater.
                    - INSIVUMEH

    Nov-Dec 2003    - Incandescent avalanches.
                    - 4 November explosions threw material 150 m above crater rim; 18-19
                      November, gas-and-ash plumes up to 1.2 km above the crater; 28 Nov-1 Dec,
                      700-900 m above the crater; 7-9 December, 500 m above crater; 10-16
                      December, 200-1000 m above the crater, and 18-22 and 30 December,
                      'low-level plumes.'
                    - INSIVUMEH

Tremor was common and at times abundant during 2003, including in the last two months of the year. On 21 November, almost continuous harmonic tremor was detected for a span of 21 hours. On 23 November intervals of tremor lasted between 0.5 and 3 hours.

The Washington VAAC archive contains 48 ash advisories on Fuego. The number of these advisories were as follows, during the stated months of 2003: 14 advisories in January (on the 8th, 9th, 11th, 12th, and 20th); 11 in April (on the 17th, 28th, 29th, and 30th); eight in May (1st and 2nd); three in June (30th), six in July (1st, 9th, and 10th), two in August (7th), two in September (29th); and two in October (9th). The most impressive plumes depicted in satellite-based graphics were for 28 April-1 May 2003, when they often stretched well out to sea, reaching ~ 160 km SW from Fuego. Otherwise, the graphics generally depicted much smaller plumes, in some cases very local ones. The graphic for 28 September showed small plumes from Fuego as well as simultaneous ones from Pacaya and Santa María.

Information Contacts: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), Unit of Volcanology, Geologic Department of Investigation and Services, 7a Av. 14-57, Zona 13, Guatemala City, Guatemala (URL: http://www.insivumeh.gob.gt/); Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch, NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/); Charles R. Holliday, Air Force Weather Agency, Offutt Air Force Base, Nebraska 68113 USA; Prensa Libre (newspaper), 13 calle 9-31 zona 1, 01001 Guatemala City, Guatemala (URL: http://www.prensalibre.com/).

08/2005 (BGVN 30:08) Ongoing ash emissions, lava flows, and associated hazards into 2005

Fuego remained active into 2005, although this report focuses on the interval 31 December 2003 through 11 May 2004. A previous report discussed activity through the end of 2003 (BGVN 29:11); this report, based mainly on information from INSIVUMEH (Instituto Nacional de Sismologia, Vulcanologia, Meterologia y Hidrologia) covers the interval from end of 2003 to 11 May 2004.

Figure 7 is a map of the Fuego-Acatenango region, emphasizing drainages and settlements frequently mentioned in activity and hazard reports. Fuego is moderately close to the centers of some of Guatemala's largest cities, including the Capital (2-3.5 million inhabitants, ~ 40 km NNE of Fuego's summit) and Antigua (~ 32,000 inhabitants, ~ 18 km NNE).

Figure 7. A sketch map of Fuego and adjacent Acatenango centered several kilometers S of these edifices. Numerous drainages emerge from the stratovolcano, their paths trending radially outward as well as in many cases curving decidedly S with distance from the volcano. Abbreviations 'R.' and 'Q.' apply to the Spanish-language terms Río (river) and Quebrada (canyon, and in this region these are often steep-sided, essentially gorges). 'F' stands for finca (farm or plantation, many of which grow the renowned Antigua coffee). A few contours are shown around these volcanoes (labeled in meters above sea level). The Fuego-Acatenango complex also contains two smaller (unlabeled) topographic highs, each one a few kilometers N of the better known peaks (i.e. N of Fuego, Meseta, and N of Acatenango, Yepocapa). Several towns off the map's margins are indicated with arrows and distances. Compiled by Bulletin editors from topographic maps.

CONRED, the Guatemalan hazards agency (Cordinadora Nacional para la Reducción de Desastres) posted hazard information on their website, in part using a map format noting conditions seen from various perspectives. For example, the map issued for 9 January 2004 (during the largest crisis of the interval), included a title, a legend, a summary of critical hazards-oriented observations. One portion of the 9 January map reported a local wind velocity, N-NW at 12-18 km/hr, and the occurrence of fine and very fine ash falling within 5 to 15 km of the crater. The map also included key radio base stations and for each, a summary of the day's message content.

Many early 2005 observations were hampered by rainfall. Table 4 summarizes numerous INSIVUMEH daily reports during February, but for the bulk of the entries, it chiefly presents Smithsonian/USGS Weekly Reports to portray longer time spans.

Table 4. Samples of Fuego activity during 31 December 2003 through 11 May 2004. Summaries based largely on Smithsonian/USGS Weekly Reports are shown as multi-day intervals (marked with an asterisk, "*"). Most of the reported eruptions in column 3 were ash bearing. Courtesy of INSIVUMEH.

    Date                   Maximum plume height (above summit) and bearing
        Activity Description

    31 Dec-06 Jan 2004*    --
        During 1-5 January, lava emitted from Fuego flowed 70-100 m from the crater. Avalanches
        from the lava-flow fronts traveled W toward Santa Teresa ravine and toward Trinidad
        ravine. Seismic stations on the volcano recorded almost continuous harmonic tremor.

    07 Jan-13 Jan 2004*    ~3 km
        Ash emission starting  around 1500-1600 on 8 January (see text).

    21 Jan-27 Jan 2004*    ~1.5 km, SSW (22 Jan). Smaller explosions to ~700 m above the crater.
        Incandescent avalanches traveled a maximum distance of 1 km toward Zanjon Barranca Seca,
        La Trinidad, and Rio Ceniza ravines. Not ashfall in populated areas. ~1.5 km from two
        strong explosions (evening of 22 January); blown SSW. During the rest of the week,
        smaller explosions sent plumes to ~700 m above the crater.

    28 Jan-03 Feb 2004*    ~1.1 km
        Small-to-moderate explosions. The highest rising ash plume was produced from an explosion
        on 29 January. The plume reached above the crater and was accompanied by avalanches of
        volcanic material down Barranca Seca. A small amount of ash fell in Panimache village and
        possibly in Santa Sofia. On 31 January two small collapses in the S edge of the central
        crater produced small avalanches of lava blocks.

    16 Feb 2004            0.3-1 km, SW
        Audible acoustic shock waves. Ashfall on upper edifice.

    17 Feb 2004            --
        Incandescent avalanches rose 200 m at night, but some traveled into the drainages of the
        Taniluya, Ceniza, and Zanjon Barranca Seca. A mudflow descended the Quebrada Santa Teresa
        (on Fuego's W-SW sides) carrying blocks up to 2 m in diameter. During 0855 to 1140 Fuego
        produced 10 explosions characterized as strong, resulting in warnings to civil aviation
        authorities. Ashfall on W- and SW-flank communities.

    18 Feb 2004            1.5-1.7 km
        A rapid succession of 15 early morning explosions at 10- to 30-second intervals were
        heard up to 8 km distant from the summit. Incandescent material landed on many of the
        upper slopes. Judging by the quantity and weight of ash fall, INSIVUMEH inferred that the
        eruption caused substantial changes in the summit area. Finer ash fell for 10 to 15
        minutes on Finca Sangre de Cristo and environs. Besides aviation safety, concerns
        included drinking-water contamination. Ashfall up to 8 km from summit.

    20 Feb 2004            1.5-2 km; light to moderate S winds
        Loud outbursts and incandescent avalanches down the W-flank valleys of the Seca,
        Taniluya, and Trinidad rivers, and to lesser extent down SE-flank valleys of the Las
        Lajas-El Jute rivers. Ash-bearing emissions came from the central crater at 4- to
        9-minute intervals. Some traces of ash noted to the N, in the Capital.

    25 Feb-02 Mar 2004*    ~1.7 km
        Weak-to-moderate explosions continued at Fuego, producing plumes above the crater.
        Avalanches of volcanic material traveled down several ravines, including Trinidad,
        Ceniza, Santa Teresa, and Taniluya (to the W). Explosions on 28 February deposited small
        amounts of fine ash in the village of Sangre de Cristo, and explosions on 29 February
        deposited ash W and SW of the volcano in the villages of Yepocapa and La Cruz.

    04 Mar-08 Mar*         ~1.5 km
        On 5, 7, and 8 March avalanches of incandescent volcanic material traveled as far as 1.5
        km down several ravines, including Seca, Taniluya, Ceniza, and Trinidad. Explosions on
        the 7th and 8th deposited ash 6-10 km from Fuego, including in the villages of Sangre de
        Cristo and Panimache.

    10 Mar-16 Mar 2004*    ~1.7 km
        Explosions; incandescent avalanches as far as 600 m down ravines on the volcano's W, SW,
        and S flanks; ash fell in W- to SW-flank settlements from Sangre de Cristo to Panimache
        and Finca Morelia.

    17 Mar-23 Mar 2004*    ~1.3 km
         Volcanic material traveled down the Seca ravine; ash fell in the village of Sangre de
         Cristo.

    24 Mar-30 Mar 2004*    ~1 km
        Three strong explosions were recorded on 26 March; they caused incandescent avalanches in
        the Zanjon Barranca Seca and Trinidad ravines. On 29 March two explosions within 7
        minutes produced ash plumes. A lahar occurred on 29 March in the Zanjon Barranca Seca
        ravine.

    31 Mar-06 Apr* 2004    ~1.2 km (5 April, drifting SSE)
        Lahars flowed down Seca Ravine on 30 March, and passed near the village of Sangre de
        Cristo on 3 April. Incandescent avalanches descended several ravines, including Santa
        Teresa, Ceniza, and Taniluya.

    07 Apr-13 Apr 2004*    ~1 km
        Lava flowed 75-100 m from the central crater and avalanches of volcanic material traveled
        as far as 400 m towards Santa Teresa and Taniluya ravines.

    14 Apr-20 Apr 2004*    ~2.3 km (16 April, drifting S)
        During 18-19 April, small eruptions hurled incandescent material up to 50 m above the
        vent.

    21 Apr-27 Apr 2004*    ~1 km (steam)
        Weak explosions produced steam clouds above the volcano. In addition, small avalanches of
        volcanic material occasionally traveled W toward Santa Teresa Ravine.

    28 Apr-04 May 2004*    ~1.5 km
        Ash-bearing explosions. On 28 April, an explosion produced an ash plume above the
        volcano, and ash was deposited ~4 km SW of the volcano in the villages of Panimache I and
        Panimache II. In addition, a small volcanic avalanche traveled W toward the Santa Teresa
        ravine.

    05 May-11 May 2004*    --
        Explosions chiefly produced gas-and-ash clouds. On 5 May a small lahar traveled to the W
        down Seca ravine.

From the table, the pattern emerges of ongoing emissions with frequent plumes to 1 km and occasional higher plumes (several to ~ 2 km and one to ~ 3 km). Similar to previous months, the reports frequently mention dislodged lava blocks and mass wasting of volcanic materials.

The highest plume found in available reports of the interval occurred on 8 January 2004, when an ash plume rose ~ 3 km over the summit. Traces of ash fell in the Capital during this episode.

Fuego began its 8 January eruption around 1500 to 1600, expelling thick, broad columns of gases and ash to ~ 3 km above the crater. There were 25-30 explosions a minute accompanied by loud rumbling noises and acoustical shock waves felt 12 km away. Although no evacuations were ordered, settlements on the upper flanks were considered at risk, including San Andrés Iztapa, Chimaltenango, Comalapa, San Martín Jilotepeque, San José Poaquil, and Yepocapa.

The Washington VAAC added these observations: "[GOES 12] satellite imagery shows two plumes moving away from the volcano. The higher plume extends approximately 75 nm [~ 140 km] to the [N] and is estimated to be around FL250 [shorthand for 25,000 feet altitude, ~ 8 km]. A lower plume extends approximately 70 nm [126 km] to the [W] and is estimated to be up to FL190 (19,000 feet altitude, ~ 6 km). Hot spot activity has been fairly strong and constant over the past several hours."

A 20 February report described continued vigorous activity; ash emissions from the central crater rose to heights of 1.5-2 km above the summit (table 1). Light to moderate winds again blew the ash N and some traces fell in the Capital.

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala; Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (NOAA/NESDIS), 4700 Silver Hill Road, Stop 9910, Washington, DC 20233-9910, USA (URL: http://www.ssd. noaa.gov/).

11/2007 (BGVN 32:11) Variable explosive activity continues sporadically, July 2005-December 2006

Fuego was previously discussed in BGVN 30:08. This report discusses ongoing developments at Fuego since July 2005 and through December 2006. In general, the volcano erupts vesicular, olivine-bearing basaltic lava flows. They traveled from the central crater hundreds of meters down the S, SW and W flanks, and the lava flow fronts released occasional blocky avalanches of incandescent material. The latter process is generally omitted from the rest of this report unless the avalanche(s) were particularly noteworthy, as in cases where pyroclastic flows were also noted.

On 17 July 2005, an ash plume ~ 3.5-4 km high accompanied small pyroclastic flows down Santa Teresa and Taniluyá ravines. This activity continued sporadically through October 2005.

From 2-7 November 2005, weak explosions and low ash plumes occurred along with lava flows that traveled down the volcano's S and SW flanks, extending 600 m towards the Taniluyá ravine, and 300 m towards the Cenizas ravine. On 14 November, two lava flows traveled from the S edge of the central crater 150 m toward the Cenizas ravine, and 400 m toward the Taniluyá ravine. A third lava flow traveled 600 m W towards the Santa Teresa ravine. Between 17 and 21 November, lava flows traveled S towards the Cenizas and Taniluyá ravines and W towards Santa Teresa ravine.

On 13 December 2005, two lava flows from Fuego extended 200-300 m W and SW of the central crater. On 27 December 2005 an ash plume rising ~ 7.6 km altitude extended SSW and SSE of the volcano; lava flows traveled ~ 2 km S down Taniluyá ravine, and W down Seca ravine, initially extending ~ 800 m and 1,200 m, respectively.

At 0602 on 27 December, a pyroclastic flow descended S. Ash fell S of the volcano in the port of San Jose. Later that day, lava flows extended 1.2 and 1.3 km, and pyroclastic flows descended 1.8 and 2 km down the Taniluyá and Seca ravines, respectively. Lava flows also traveled W toward Santa Teresa ravine, and SE towards the Jute and Lajas ravines. An ash plume rose ~ 7.6 km, and a small amount of ash fell W and SW of the volcano in the villages of Morelia, Santa Sofía, Los Tarros, and Panimaché (~ 7 km SSW). This activity continued through 29 December with more lava flows and bombs. The emissions hurled incandescent lava clots ~ 75 m high, spawned lava flows, and generated a dark plume rising to ~ 1 km above the crater rim.

January 2006 activity was essentially a continuation of December's with moderate-to-strong explosions and incandescent lava ejecta hurled ~ 40 m high. Explosions could be heard 25-30 km away. The explosions were accompanied by rumbling sounds and acoustic waves that shook windows and doors in villages near the volcano. Ash plumes rose ~ 1 km to ~ 1.5 km. On 22-23 January, there were Strombolian lava ejections rising ~ 100 m above the crater rim accompanied by block avalanches down the SW flank.

During February and March 2006, explosions moderated but activity continued. Weak-to-moderate explosions occurred; shock waves were sometimes felt in villages near the volcano. On 6-7 March, ash emissions up to ~ 4.6 km altitude were visible on satellite imagery.

From 22 through 28 March, Fuego ejected incandescent material up to ~ 50-75 m and gas plumes to ~ 300 m above the crater rim. Short pyroclastic flows from avalanches occurred on the upper flanks. On 28 March, pyroclastic flows traveled ~ 450 m S, and avalanches occurred from the lava-flow fronts.

On 17 April 2006, explosive ejections threw lava ~ 50-75 m above crater rim, and gas plumes rose to ~ 150-200 m. Lava flowed ~ 400 m S towards Taniluyá ravine.

During 17-18 May 2006 lava flows reached ~ 100 m SW towards the Taniluyá river and ~ 500 m SW towards the Cenizas river. Fumarolic gases rose to ~ 600 m above the crater rim and drifted E and W.

On 29 June 2006 fumarolic gases rose to ~ 125 m , spatter to tens of meters, and ash plumes ~ 2.2 km respectively above the crater rim. Lava flows extended ~ 400 m SW toward the Cenizas river. Pyroclastic flows traveled mainly SW along the Cenizas river, with a lesser number moving SW along the Taniluyá river.

On 3 July 2006, explosions discharged incandescent material hundreds of meters above the central crater and avalanches traveled ~ 300-500 m SW along the Cenizas river.

The only activity reported in August occurred on the 16-17th, when ash explosions reached 300-800 m above the crater rim, and explosions of incandescent material produced avalanches that descended 300-500 m SW towards the Cenizas, Taniluyá, and Santa Teresa river valleys.

The latter half of September 2006 continued the characteristic previous activity with explosions that sent incandescent lava 75-100 m above the crater rim and that generated hot avalanches SW towards the Taniluyá River.

On 15 November, lava flows traveled about 150 m SW, and avalanches occurred from the lava-flow fronts. On 17 November, three out of seven explosions propelled incandescent material 100 m above the central crater rim. Relative quiescence followed through December 2006.

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala; Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (SAB), NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Rd, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC/).

12/2007 (BGVN 32:12) Moderate Strombolian eruptions, including pyroclastic flows, continue into early 2008

Eruptive activity has continued at Fuego between January 2007 and early February 2008. Typical activity during this interval consisted of explosions that generated ash plumes up to ~ 2 km above the summit (~ 6 km altitude) and caused local ashfall (reported up to ~ 15 km away, but from one eruption, ~ 25 km away). Strombolian eruptions, avalanches, and lava flows up to ~ 1.5 km long were also commonly reported. Pyroclastic flows traveled up to ~ 2 km. Blocks detaching from the front of the flows and bouncing downslope were often incandescent. Satellite imagery often detected hotspots. Shock waves and rumbling or loud noises, sometimes described as similar to a passing airplane, were commonly noticed. Out last report discussed events through December 2006 (BGVN32:11).

Details included in the text below were provided by the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), the Coordinadora Nacional para la Reducción de Desastres (CONRED), and the Washington Volcanic Ash Advisory Center (VAAC).

The photographs included in this report are by Richard Roscoe, who on his website (www.photovolcanica.com) features more Fuego photos than we can include here. He also includes a brief animation of a small Fuego eruption. His site also provides a beginner's guide to volcano photography as well as cautions about safety and trekking in the area. All of his photos are used with his permission. They were taken during 29-31 December 2007. A companion site by his colleagues M. Rietze and Th. Boeckel also describes their photo excursion. Figures 8-10 are broadly representative of the kinds of eruptions common at Fuego during the reporting interval, and they provide a feel for the regional setting and geography.

Figure 8. A view of Fuego in eruption as seen from the city of Antigua. Note twin church spires along the photo's lower margin. Fuego (erupting at left) is only one of several volcanoes in this photo; progressively farther towards the right peaks consist of Meseta, Acatenango (highest), and Yepocapa. This copyrighted photo is from around 29-31 December 2007. Used with permission of photographer Richard Roscoe.
Figure 9. An explosive plume rising vertically above Fuego's summit on 29 December 2007, with wisps of falling ash visible on the right side. The photo was taken from Antigua. Copyrighted photo by Richard Roscoe.
Figure 10. Incandescent ejecta from Strombolian eruptions of Fuego taken from the N on Acatenango volcano (~ 4 km elevation). The exact date was surmised from text as 30 December 2007. The shape of Fuego's summit has been modified by the growth of a sharp peak, presumably due to the accumulation of spatter and cinder. The night-time exposure also captured in the background the lights of towns on the Pacific coastal plain to the S. Copyrighted photo by Richard Roscoe.

During 4-5 January 2007 gas-and-ash clouds rose to 4.2-4.8 km altitude and constant incandescent avalanches from the central crater and a lateral crater ~ 70 m from the S edge of the central crater descended SW towards Taniluyá ravine. Fine ashfall was noted in areas S and ~ 9-15 km SW of the summit. On 12 January there was explosive ejecta and ash plumes up to 4 km altitude. Incandescent material was propelled up to 75 m above the summit and incandescent blocks rolled W towards Taniluyá ravine and Santa Teresa ravine, and S towards Cenizas ravine. Explosive activity was reported again during 21-29 January when incandescent material and blocks were ejected 100 m above the summit; blocks rolled ~ 500 m S and SW. On 26 and 29 January glowing blocks from lava-flow fronts rolled S towards Cenizas ravine. During an overnight visit to a neighboring summit, Craig Chesner and Sid Halsor saw Strombolian eruptions at roughly half-hour intervals.

No activity was reported after late January until 9-13 March 2007, when lava flows were noted extending ~ 100-150 m W toward Taniluyá ravine and explosive ash plumes rose to 4-4.2 km altitude. On 12 March glowing material was ejected ~ 15-20 m above the central crater. Lava flows on 15 March and explosive incandescent ejecta thrown 200 m above crater rim were accompanied by an ash plume. The longest lava flows traveled ~ 1.5 km W toward Taniluya ravine. Similar activity continued the next day, with previous lava flows advancing and new flows seen in different ravines. Pyroclastic flows also occurred, ash plumes rose to 4-6 km altitude. Shockwaves were felt ~ 15 km away, and Strombolian eruptions propelled glowing tephra 300 m above the summit. Two pyroclastic flows traveled about 800 m; one NW, and another W and SW. During most days 21-27 March Fuego emitted explosive gas-and-ash plumes that rose to ~ 4.7-5.1 km altitude, causing ashfall in areas 5-8 km SSE and 9 km W. On 24 March explosions were followed by lava blocks rolling down the W flank toward Taniluyá ravine. Similar activity on 26 March caused ashfall in areas 10-25 km to the W and SE.

The next reports of activity, during 20-23 April, were of lava flows, pyroclastic flows, explosive incandescent ejecta 50-75 m above the vent, and a gas-and-ash plume up to 4 km altitude. Incandescent material descended 300 m down the S and W flanks. The Washington VAAC reported that an intense hotspot seen on satellite imagery on 21 April was likely caused by a lava flow to the SW. On 23 April a pyroclastic flow and incandescent avalanches traveled down SE and SW ravines; ash explosions caused light ashfall in areas S.

Observations during 17-19 May were of fumarolic emissions ~ 600 m high along with active lava flows extending ~ 100 m SW toward the Taniluyá ravine and ~ 500 m SW toward the Cenizas ravine. The lava flow from the edge of the central crater continued on the S flank (~ 150 m long); landslides of blocks of incandescent material spalled from the front of the flow into the Taniluya ravine. Activity the following week, 26-27 May, consisted of explosive ejecta ~ 100 m above vent, gray steam-and-ash plumes up to 4-4.6 km altitude, and block avalanches to the S and SW. On 28 May the lava flow on the S flank continued to advance and produce incandescent blocks that rolled W in Taniluya ravine. Explosive incandescent ejecta was seen on 29 May, along with lava flows that extended ~ 400 m SW toward Cenizas ravine and incandescent material rising tens of meters above the vent.

On 1-2 August, pyroclastic flows occurred and explosive ejecta was thrown 50-75 m above the crater rim; an ash plume rose to 5.3 km altitude. Incandescent avalanches traveled 500-700 m down the S and W flanks. On 2 August, a moderate eruption produced a pyroclastic flow that traveled ~ 2 km SSW down the Cenizas ravine. A resultant plume produced ashfall S, SW, and W for several minutes.

On 8-9 August, pyroclastic flows and explosive Strombolian activity occurred with a gas-and-ash cloud to 4.4-5.6 km altitude. This eruption was visible from the city of Antigua, even though the resulting lava flows primarily traveled down the S and W flanks, which were on the side opposite from Antigua. Clouds obscured the view of possible E-flank lava flows. Ashfall was reported in areas to the W. Lava flows and related detached blocks traveled 1.5 km down Cenizas ravine to the SW. Several pyroclastic flows descended the flanks. Ashfall was reported in villages to the W, SW, and S.

On 10-13 August, small explosions and ash plumes rose up to 4.3 km altitude. 11 August behavior was characterized by weak explosions that expelled gray ash to 500 m above the crater. On 27 August, lahars carried tree trunks, branches, and blocks down the Lajas drainage to the SE. On 28 August, explosive ash plumes rose to 4.1 km altitude. On 31 August, a lahar 8 m wide and 1.5 m thick descended W down the Santa Teresa ravine.

On 3-4 September, explosive ash plumes rose to 4.5 km altitude. On 3 September, fumarolic plumes rose to 4 km altitude and a 300 m lava flow traveled W down the Taniluya drainage. There were also avalanches in the Cenizas ravine. On 21 September explosions of gray ash rose to ~ 5.8 km altitude and incandescent pulses in the crater rose to 75 m with avalanches in the S and SW flank. On 24 September 2007, moderate and strong explosions occurred, accompanied by ash plumes extending up to 900 m above the crater, and constant degassing sounds for periods of up to 20 min. On 5 October, weak to moderate incandescent explosions occurred, accompanied by ash plumes up to 800 m above the crater, and degassing sounds. Block avalanches were noted in the Taniluyá and Santa Teresa ravines.

On 10 October, weak to moderate explosions occurred, the largest accompanied by ash plumes that rose to 4-5 km altitude. Avalanches from cone building in the inner crater went W into the Taniluyá and Santa Teresa ravines.

On 12 October, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose to altitudes of 4.2-4.8 km and caused ashfall in areas to the W. The explosions were accompanied by rumbling, and degassing sounds; shock waves were detected up to15 km away. The Washington VAAC reported a thermal anomaly on satellite imagery along with ash plumes that drifted W and NW.

According to Washington VAAC, satellite imagery detected multiple ash "puffs" emitting from the volcano between 24-30 October. They also reported ash plumes on 20 November (4.6 km in altitude) and 29 November. Additional weak to moderate explosions occurred on 7 December and 12 December, expelling ash and causing degassing sounds. Shock waves were noticed up to 15 km away.

On 15 December, Fuego generated a significant ash-and-steam plume that was observed from Antigua and Guatemala. It also produced a considerable flow of ash (and possibly lava) down its E slopes. According to the Washington VAAC, satellite imagery detected a thermal anomaly on 15-16 December. Thereafter, Fuego's activity declined to normal levels, although a few moderate explosions continued, along with an occasional ash plume. An ash cloud from Fuego was observed on 21 December and 26 December 2007.

For 11 January and 24 January 2008, INSIVUMEH reported weak explosions from Fuego that produced ash plumes that rose to altitudes of 4-5 km. Small avalanches of blocks traveled W toward the Taniluyá ravine. Based on reports from INSIVUMEH, CONRED reported on 28 January that the Alert Level was lowered to Green. On 30 January, satellite imagery detected a narrow plumes of gas and possible ash. On 4 February, satellite imagery detected ash plumes that rose to an altitude of 5 km.

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala; Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (NOAA/NESDIS), 4700 Silver Hill Road, Stop 9910, Washington, DC 20233-9910, USA (URL: http://www.ssd.noaa.gov/); Richard Roscoe, PhotoVolcanica.com (URL: http://www.photovolcanica.com/); M. Rietze, R. Roscoe, and Th. Boeckel, (website) Volcanoes of Central America, Volcan Fuego, Guatemala 29th-31st of Dec. 2007 (URL: http://www.tboeckel.de/EFSF/efsf_wv/fuego_07/fuego_07_e.htm); Craig Chesner, Eastern Illinois University, Charleston, Illinois, USA; Sid Halsor, Wilkes Barre University, Wilkes Barre, PA 18766, USA.

12/2009 (BGVN 34:12) Many small ash plumes and some lava flows during 2008-2009; instrumented study

The current eruption from Fuego, located ~40 km WSW of the country's main airport (La Aura) and 17 km NE of the historic city of Antigua, has been ongoing since 2002. The Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) monitors this volcano, providing regular observations. During the current reporting interval, 11 January 2008-12 January 2010, minor ash plumes were common, typically rising several hundred meters above the summit (tables 5 and 6). Some were incandescent. Plumes often drifted 5-15 km from the vent and residents in the region sometimes noted noise and shock waves. Observers occasionally saw avalanches and lahars, and sometimes an active lava flow traveled ~100 m from its vent. On 30 January 2009 observers saw incandescent material ejected 50-100 m above the crater and avalanches from the crater rim descended multiple ravines.

Table 5. Summary of reported activity at Fuego volcano for January 2008-December 2008. "?" indicates no activity. Information courtesy of INSIVUMEH, Washington Volcanic Ash Advisory Center (VAAC), and HIGP Thermal Alerts System.

Table 5. Summary of reported activity at Fuego volcano for January 2008-December 2008. "—" indicates no activity. Information courtesy of INSIVUMEH, Washington Volcanic Ash Advisory Center (VAAC), and HIGP Thermal Alerts System.

    Dates               Explosions                        Ash Plumes
                                                          Altitude (km)    Drift
        Other observations

    11 Jan 08           weak                              4.1-4.3          --
        Alert Level Yellow

    24 Jan 08           shock waves detected 3 km away    4.2-4.5          S, SW, W
        Avalanches of blocks traveled W towards Taniluya ravine; Alert Level lowered to Green

    04 Feb 08           multiple                          5                W

    06-19 Feb 08        multiple                          4-4.7            --
        Fumarolic plumes

    22-25 Mar 08        4-5/hour                          4.1-4.6          6-8 km; S, SE
        Noise/shock waves felt 5-8 km distant

    31 Mar-01 Apr 08    multiple                          --               SW

    15-21 Apr 08        1-2/hour                          4.3-4.7          5-8 km SW
        Noise/shock waves felt 5-15 km distant 

    28 Apr 08           1/hour                            4.4              5 km SW
        Noise audible 15 km distant

    22-27 May 08        multiple                          4.1-4.5          5 km SW
        Noise/shock waves felt 10-15 km distant; constant avalanches of blocks traveled W towards
        Taniluya and Santa Teresa ravines

    28-30 May 08        many                              4.1-4.4          S, SW
        Noise/shock waves felt several km away; avalanches of blocks traveled W into Taniluya and
        Santa Teresa ravines

    02 Jun 08           --                                --               --
        Incandescent material ejected 50-100 m above crater; small lava flow traveled 100 m W
        towards Santa Teresa ravine

    13-17 Jun 08        --                                3.9-4.4          --
        On 13 Jun lahars descended Santa Teresa (W) and Ceniza (SW) drainages; a lava flow
        traveled 100 m towards Santa Teresa; on 15 Jun rumbling noises accompanied by shock
        waves; on 17 Jun fumarolic plumes noted and incandescent material ejected ~50 m above
        crater

    18 Jun 08           --                                4.3              W, SW
        Incandescent material ejected 50 m above crater; constant avalanches of blocks traveled
        W; rumbling/degassing noises

    20 Jun 08           --                                --               --
        Lahar that was hot in areas descended Ceniza drainage to SW, dragging tree branches and
        blocks 0.5-1 m in diameter

    04 Jul 08           multiple                          --               --
        Lava flow traveled 100 m W toward Santa Teresa ravine; lahar carrying blocks descended
        Ceniza ravine to SW

    7-8 Jul 08          many                              4-4.5            S, SE, SW
        Incandescence at summit; constant avalanches of blocks from lava-flow fronts descended W
        flank

    31 Jul 08           --                                --               --
        Lahar descended El Jute River to SE

    01 Aug 08           many                              4.1              W, SW
        Rumbling noises and shockwaves occasionally accompanied explosions

    20 Aug 08           --                                --               --
        Lahars descended several rivers carrying blocks up to 1 m diameter

    25-26 Aug 08        many                              4.1              SW
        300-m long lava flow traveled W towards Santa Teresa ravine

    18 Sep 08           --                                4.3              SSW

    24 Sep 08           many                              4.1              W
        Lava flow traveled 300 m W towards Seca ravine; avalanches generated by lava flow front

    20-21, 25 Nov 08    many                              4.1-4.6          W, S
        Rumbling/degassing noises and shock waves detected 10 km away; lava flowed 150 m towards
        Taniluya ravine; incandescent material rolled down flanks

    12 Dec 08           many                              4.1-5            SSW
        Rumbling/degassing noises and shock waves detected 10 km away

Table 6. Summary of reported activity at Fuego volcano for January 2009-January 2010. "—" indicates no activity. Information courtesy of INSIVUMEH, Washington Volcanic Ash Advisory Center (VAAC), and HIGP Thermal Alerts System.

    Dates               Explosions                        Ash Plumes
                                                          Altitude (km)    Drift
        Other observations

    4-6 Jan 09          multiple                          4.1-5.1          12 and W, SW
        Rumbling noises and shock waves detected 10 km away; constant avalanches of blocks
        descended S and SW flanks

    8-9 Jan 09          3-5/hour                          4.3-5.4          10-15 km; S, SW
        Rumbling noises and shock waves detected 10-15 km away; constant avalanches of blocks
        descended S and SW flanks

    19-20 Jan 09        many                              4.1-4.6          7 km; W, W, SW
        Some explosions produced rumbling sounds; avalanches occurred on S and SW flanks;
        MODIS/MODVOLC thermal alerts 23 and 25 Jan

    30 Jan, 3 Feb 09    multiple                          4.1-4.7          S, SE
        Some explosions produced rumbling sounds and shock waves; fumarolic plumes rose 100 m
        above crater; on 30 Jan incandescent material ejected 50-100 m above crater and
        avalanches from crater rim traveled down multiple ravines

    6, 8, 10 Feb 09     multiple                          4.1-5.4          S, SW
        Some explosions produced rumbling sounds; constant avalanches of blocks; MODIS/MODVOLC
        thermal alerts 5 and 10 Feb 

    20, 24 Feb 09       many                              4.1-4.7          6-8 km SW
        Some explosions produced rumbling sounds and shock waves; incandescent material ejected
        150 m above crater; incandescent avalanches of blocks traveled down W and SW flanks

    6, 10 Mar 09        many                              4.2-4            12-15 km; S, SW
        Some strong explosions produced rumbling sounds; shock waves detected 8 km away;
        avalanches of blocks; MODIS/ MODVOLC thermal alerts 4 and 7 Mar

    12, 16, 17 Mar 09   many                              4.2-4.8          S, SW
        Incandescent material ejected 75 m into air; some explosions produced rumbling noises

    27, 30 Mar 09       many                              4.1-4.8          S, SW
        Some explosions produced rumbling sounds; shock waves detected 10 kn away; avalanches of
        blocks down W and SW flanks; on 30 Mar incandescent material ejected 75 m into air

    24, 28 Apr 09       many                              4.1-4.8          10 km SW
        Some explosions produced rumbling sounds; shock waves detected 5 km away; avalanches of
        blocks; fumarolic plumes rose 50-150 m and rifted S,NW, N; on 28 Apr incandescent
        material ejected 75-100 m into air; MODIS/MODVOLC thermal alerts 7, 12, and 15 Apr

    21 May 09           --                                --               --
        Lahars descended Santa Teresa and Ceniza ravines to W and SW, carrying blocks up to 2 km
        diameter; MODIS/ MODVOLC thermal alert 16 May

    25-26 May 09        many                              4.1-4.7          W, SW, S, SE
        Some rumbling noises; on 25 May fumarolic plumes rose to 4.2 km and drifted S, SE

    5, 8, 9 Jun 09      many                              4.1-4.7          10 km; W, SW, S
        Some rumbling noises; shock waves detected 12-15 km away; avalanches descended several
        ravines; fumarolic plumes rose 100 m and drifted S, SW

    10, 14 Jul 09       many                              4.1-4.6          10-15 km; W, SW
        Some rumbling noises and shock waves; incandescent material ejected 75 m and avalanches
        descended several ravines; fumarolic plumes rose 100 m and drifted S, SW

    31 Jul, 3 Aug 09    many                              4-4.6            W
        Some rumbling noises; incandescent materials ejected 75 m; avalanches occurred; fumarolic
        plumes rose 200 m and drifted W, NW

    2-3 Aug 09          frequency increased               --               --
        MODIS/MODVOLC thermal alert 7 Aug

    21, 25 Aug 09       many                              4.2-4.6          5-7 km; W, SW
        On 21 Aug rumbling noises accompanied by incondescent tephra ejected 75 m high;
        MODIS/MODVOLC thermal alert 31 Aug

    10, 14 Sep 09       many                              4.1-4.7          10 km; W, SW, S
        Some explosions accompanied by rumbling noises and shock waves; incandescent material
        ejected 100 m high; avalanches descended multiple ravines

    9, 12, 13 Oct 09    many                              4.1-4.6          W
        Rumbling noises; avalanches of blocks; on 9 Oct lahar traveled down Lajas ravine carrying
        blocks up to 50 cm in diameter

    21 Oct 09           --                                --               55 km S

    26 Oct 09           many                              4.4-4.8          10 km; S, SW
        Rumbling/degassing sounds; avalanches of blocks

    13 Nov 09           many                              4.2-4.7           7 km S
        Rumbling noises and incandescence noted; white fumarolic plumes rose 100 m and drifted
        S, SW.

    30 Nov-1 Dec 09     many                              4.3-4.7           8-15 km; W, SW
        Rumbling noises noted; incandescent block avalanches generated; MODIS/MODVOLC thermal
        alerts 24, 25, and 29 Nov

    4 Dec 09            multiple                          4.2-4.7           15-18 km W
        Rumbling noises and incandescent block avalanches noted

    11, 14, 15 Dec 09   many                              4.1-4.7           8-12 km; W, SW
        Incandescence from main crater and rumbling noises noted; avalanches descended S and W
        flanks; MODIS/MODVOLC thermal alert 31 Dec

    8, 11, 12 Jan 10    many                              4-4.7             10 km; multiple
        Incandescent material ejected to heights up to 75 m; some explosions accompanied by
        rumbling noises and shock waves felt up to 7 km away; avalanches descended flanks;
        MODIS/MODVOLC thermal alerts 5, 6, and 12 Jan

Observations. A report from Michigan Technological University described multi-instrument fieldwork during 9-21 January 2009 (Nadeau and Dalton, 2009), work often amid conditions of poor visibility. The authors also credited seven other people (from INSIVUMEH and PCMI; see Information Contacts) who participated in the campaign. One of the instruments deployed was an ultraviolet (UV) camera that enabled researchers to measure SO2 emission rates with high temporal resolution. They also took concurrent seismic and infrasonic acoustic measurements, some mini-DOAS measurements, and they recorded their visual observations of volcanism. A similar campaign occurred in January 2008.

During this fieldwork, activity was dominated by passive degassing accompanied by intermittent tephra eruptions of variable size (figure 11). Explosions ranged from small puffs of ash that mixed with the passive gas plume to larger, convective columns with ejected bombs.

Figure 11. Passive degassing (left) and an explosion (right) at Fuego, December 2008-January 2009. From Nadeau and Dalton (2009).

During 9-21 January 2009, the UV camera was placed on Meseta ~1 km from the erupting vent (figures 12 and 13). An array seismo-acoustic stations was also deployed around the circumference of the vent for full azimuthal coverage. Thick clouds prohibited visibility on most days, resulting in collection of imagery on only 3 dates (12, 14, and 21 January). On 21 January several stationary mini-DOAS (differential optical absorption spectroscopy) scans of the passively degassed plume were also made for comparison with SO2 retrievals from camera images.

Figure 12. Vertical aerial photo the Fuego summit (steaming, near the bottom) and Meseta edifice. Star indicates location of UV camera during field measurements. (inset) UV camera and plume as seen from measurement site. From Nadeau and Dalton (2009).
Figure 13. A map of SO2 concentration-pathlength created from UV imagery of Fuego during the 2009 campaign. Scale bar at bottom indicates concentration pathlength in colored versions (in units of ppm-m with highest values on the scale and in portions of the plume at ~1,000 ppm-m). From Nadeau and Dalton (2009).

Preliminary evaluation of camera-derived emissions at Fuego in January 2009 show decreases in SO2 output prior to explosive events, and may indicate short-term sealing of the vent. Additionally, some small low-frequency seismic events without explosion signals in the acoustic record were associated with short-term increases in SO2 output.

A paper presented by Lyons, Waite, and Rose (2009) suggests the potential to track activity of Fuego volcano using explosive energy partitioning. This has implications for monitoring and hazard prediction.

References. Nadeau, P., and Dalton, M., 2009, Report on UV camera field campaign, Fuego and Santiaguito volcanoes, Guatemala, December 2008-January 2009, unpublished informal report accessed January 2010 (URL: http://www.geo.mtu.edu/~panadeau/)

Lyons, J.J., Waite, G.P., and Rose, W.I., 2009, Variable explosive energy partitioning during open vent activity at Fuego volcano, Guatemala 2007-2009: Constraining explosion source processes and implications for monitoring, American Geophysical Union 2009 Fall Meeting Abstract V23D-2124.

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) (National Institute of Seismology, Volcanology, Meteorology and Hydrology), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Washington Volcanic Ash Advisory Center (VAAC) (URL: http://www.ssd.noaa.gov/VAAC/messages.html); MODIS/MODVOLC Thermal Alerts, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/); Gregory Waite, John Lyons, Patricia Nadeau, Marike Dalton, and Joshua Richardson, Michigan Technological University, Department of Geological and Mining Engineering and Science, Houghton, MI, USA (URL: http://www.geo.mtu/edu/rs4hazards/, Email: http://www.geo.mtu.edu/~panadeau/ and http:/www.geo.mtu.edu/~mpdalton/); Kyle Brill, Jemile Erdem, and Jesse Silverman, PCMI (Peace Corps, Master's International Program), Michigan Technological University; Amilcar Cardenas (INSIVUMEH).

06/2011 (BGVN 36:06) Frequent plumes and avalanches; occasional incandescence and lahars

As previously noted, minor plumes, occasional avalanches, and lahars were reported at Fuego during January 2008-January 2010 (BGVN 34:12). Explosive activity occurred with a similar style from 2002 through December 2010, although the report heights of ash plumes was seldom over 1 km during February to December 2010. As is typical, the bulk of the reporting on Fuego comes from INSIVUMEH (the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia) and collaborating agencies. The tallest plumes of this interval reached 1.2 km (on 23 December 2010).

This report first presents the February to December 2010 summary, followed by a May 2011 photo. In the next subsection we skip back in time to discuss observations from a visit to Fuego in February 2009. In the final subsection, we note some 2010-2011 studies made at Fuego.

The February to December 2010 information in this report was initially synthesized and edited by Dan Eungard, as part of a graduate student writing assignment in a volcanology class at Oregon State University under the guidance of professor Shan de Silva.

February through December 2010 activity. According to INSIVUMEH, typical activity during February through December 2010 included degassing plumes that rose above the crater punctuated by occasional Strombolian and Vulcanian explosions that produced small ash plumes. These plumes would occasionally rise to 1.2 km above the summit and become large enough for ash to reach local communities, including Alotenángo (8 km ENE), Ciudad Vieja (13.5 km NE), San Miguel Dueñas (10 km NE), Antigua Guatemala (18 km NE), Sangre de Cristo (9.5 km WSW), Yepocapa (9 km WNW), Morelia (11.5 km SW), and Panimache (9 km SW). Major ashfall events occurred on 2-4 March, 10 June, 19 July, 27 August, 13 and 21 September, 28 October, and 22 November 2010 (table 7). Explosions would occasionally generate shockwaves that rattled windows of structures within 15 km of the summit.

Table 7. Summary of activity reported at Fuego during February to December 2010. "?" indicates no reported data. Shaded rows indicate dates with lahar events. Terms for explosion frequency: Few signifies undisclosed or under 5; Multiple, 5-20; Many, over 20. Information courtesy of INSIVUMEH and Washington Volcanic Ash Advisory Center (VAAC).

DateExplosionsAsh plume height (m)DriftIncandescence (m)Avalanches
8 Oct Multiple 600-800 S 100
11 Oct Many 500-800 S-SW
14 Oct Many 1000 SW 125 x
18 Oct Multiple 800 12 km W-S 100 x
22 Oct Multiple 500-700 SW weak x
26 Oct Many 500 N-NW 75 x
28 Oct Multiple 400-600 W-NE 75 x
29 Oct Multiple 300-500 W-SW 75 x
31 Oct Few 20 km W
5 Nov Few 900 E
8 Nov Few 900 12 km E 100 x
12 Nov Few 800 S-SW weak x
13 Nov Few 37 km SW
19 Nov Few 1000 10 km W 100 x
22 Nov Many 900-1000 15 km SW
25 Nov Few 300 W-NW
4 Dec Few SW
6 Dec Few 900 6 km SW
8 Dec Few 500 S-SW x
10 Dec Few SW
17 Dec Few 300-800 E-SE
20 Dec Few 500 W-NW
22 Dec Few 28 km NW
23 Dec Many 600-1200 10-15 km SE
24 Dec Multiple 400 N
28 Dec Few 500 5 km S-SW weak x
30 Dec Many 600-800 8 km W-SW x

Antigua Guatemala, a major tourist location with a local population of ~40,000, has occasionally experienced ashfall from Fuego and Pacaya volcanoes (Pacaya is ~30 km ESE of Fuego). Ashfall was heavy enough to damage infrastructure and collapse roofs in the town of Yepocapa during the 1971 and 1974 eruptions of Fuego. Tephra thicknesses of 300 mm with 50 mm bombs were recorded in the area of Yepocapa during the 1971 eruption, causing 20% of the roofs to collapse "including those of many public buildings" (Bonis and Salazar, 1973). From several case studies, including Fuego, Stromboli, and Deception Island, R.J. Blong (1984) suggests a 100 mm threshold for tephra thickness on roofs. Greater thickness may mean serious structural damage, especially if rainfall accompanies or follows the tephra load.

INSIVUMEH issued civil-aviation alerts several times throughout 2010 due to large ash outputs from Fuego. Washington VAAC released advisories for ash plumes including those that occurred on 31 October; 12-13 November; and 4, 10, and 22 December. Over the course of the year, plume height averaged 530 m above the summit. The plumes drifted laterally up to 37 km from the summit and frequently drifted W, SW, S, and NW.

During the year, local reports and INSIVUMEH observations noted block avalanches within the crater and on the slopes; occasionally they were large enough to reach vegetation. Incandescent pulses were fairly common during Strombolian eruptions and juvenile material reached heights up to 125 m.

Lahars were reported on 20 and 30 April, 29 May, 16 June, 21 September, and 2 October 2010. Flooding from tropical storm Agatha triggered destructive landslides and lahars on 29 May 2010. Rivers affected included the Seca (SW), Taniluya (SW), Pantaleon (W), Ceniza (SW), Las Lajitas (SE), and El Jute (SE, see figure 14) BBC News reported that in Guatemala alone, at least 83 fatalities occurred during the storm and ~112,000 people were displaced countrywide. The lahar on 16 June reportedly caused minor road damage.

Figure 14. The El Jute river channel was a site of major lahar activity at Fuego during tropical storm Agatha in May 2010. This photo was taken 8.7 km SSE from Fuego's summit (seen in the background). The old, dark gray lahar deposits seen here were eroded during the storm leaving this tall 5-m-high scarp. Observers in this 3 May 2011 photo included (from left to right) Marco Antonio Argueta (from the Guatemalan risk group CONRED; Coordinadora Nacional para la Reducción de Desastres), Rosalio Suruy, and Aroldo Surui. Photo by Rüdiger Escobar-Wolf (Michigan Technological University).

February 2009 photos of a minor eruption. During a field campaign, R. Escobar-Wolf visited Fuego and witnessed explosions that emitted a large number of ballistic blocks (not discussed on table 7). On 6 February he photographed the development of a small ash plume as well as a cloud of remobilized ash that rose from the summit area. Figure 15A was taken seconds after the central plume erupted from the summit. Figure 15B shows continued rise of the plume as well as the onset of remobilized ash from the flanks. Figure 15C is a close-up of the central ravine where, after the impact of the ballistic blocks, trails of material fell from the summit.

Figure 15. A sequence of photos (A-C) taken on 6 February 2009, viewing Fuego towards the WNW. See text for more details. Courtesy of Rüdiger Escobar-Wolf (Michigan Technological University).

Escobar-Wolf described this sequence of events as a Vulcanian eruption. The eruption was impulsive and released a central plume that reached ~ 1.5 km above the crater (figure 15B). Around the time of this photo, ballistics appeared to impact the summit and thousands of pale ash clouds rose from the summit's surface. These clouds appeared to spread widely down and along the slope, whereas rising portions dispersed (figure 15C).

Recent publications. Characterization of Fuego's activity and the development of new monitoring techniques have been ongoing for several decades. Three manuscripts were recently published focusing on seismic and gas studies.

Erdem (2010) conducted a geophysical study at Fuego from March to July 2008 using a three-component broadband seismometer and two infrasonic microphones. In order to model temporal changes in eruption dynamics, coda wave interferometry methods were used to analyze a set of highly repetitive seismic events associated with regular discrete degassing explosions. The author found rapid temporal variation in the velocity structure, which may indicate minor fluctuations in volatile content or exsolution at various depths between individual explosions. Variations in seismic and acoustic wave arrival times were used to investigate changes in explosion source depth and wind speed.

Lyons and others (2010) found a cyclic pattern in open-vent eruptive behavior at Fuego based on two years of continuous observations from the Fuego Volcano Observatory made possible by a collaboration between the Peace Corps, Guatemalan scientists, and Michigan Technological University. They found that daily observations of lava flow length and explosion characteristics have a strong correlation with satellite-based remote sensing data and tremor amplitude. The pattern of behavior is interpreted to reflect the slow accumulation and periodic gas release in a foam layer trapped in a relatively deep magma chamber or geometric trap in the conduit. This study highlights the importance of detailed geophysical and field observations as a low-cost option in developing countries, as well as in volcanological training.

Nadeau and others (2011) discuss remote sensing of SO2 emissions using a UV camera. Their analysis of 2009 Fuego data sets assessed SO2 emissions from two closely-spaced vents, compared with both visual observations and seismicity. They concluded that tremor and degassing share a common source process, and they developed a model for small, ash-rich explosions based on evidence for rheological stiffening of magma in the upper conduit. Progressive stiffening may explain why, in time-series data, there is a general increase in time lag between tremor and SO2 escape. This lag may be attributed to a deepening or a reduction in velocity of the gas rise from depth if crystallization and cooling propagates downward through time from the top of the magma column. Different degrees of stiffening and the associated range of confining pressures may cause variability in both degrees of explosivity and durations of inter-explosion quiescent periods.

References. Blong, R. J. 1984. Volcanic hazards: a sourcebook on the effects of eruptions. Sydney; Orlando, Fla., Academic Press.

Bonis, S. and Salazar, O. 1973, The 1971 and 1973 eruptions of volcano Fuego, Guatemala, and some socio-economic considerations for the volcanologist, Bulletin Volcanologique, 31 (1), 394-400.

Erdem, J. 2010, Modeling temporal changes in eruptive behavior using coda wave interferometry and seismo-acoustic observations at Fuego Volcano, Guatemala. Michigan Technological University, United States: 2010. GeoRef, EBSCOhost (accessed 19 April 2011).

Lyons, J. J., Waite, G.P., Rose, W., and Chigna, G., 2010. Patterns in open vent, strombolian behavior at Fuego volcano, Guatemala, 2005-2007. Bulletin of Volcanology 72(1): 1-15.

Nadeau, P.A., Palma, J.L., and Waite, G.P., 2011. Linking volcanic tremor, degassing, and eruption dynamics via SO2 imaging. Geophys. Res. Lett., 38: 1-5.

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH, Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/inicio.html); Washington Volcanic Ash Advisory Center (VAAC), NOAA Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC); Jemile Erdem, Rüdiger Escobar-Wolf, John Lyons, and Patricia Nadeau, Michigan Technological University, Department of Geological and Mining Engineering and Science, Houghton, MI, USA (URL: http://www.geo.mtu.edu/rs4hazards/index.htm); BBC News (URL: http://www.bbc.co.uk/); Wolfram Alfa Web Resource (URL: http://www.wolframalpha.com/).

05/2013 (BGVN 38:05) Continuous activity and a VEI 3 eruption during 13-14 September 2012

In this report we highlight Fuego’s ongoing eruptive activity during January 2011-March 2013. Elevated activity occurred during May-September 2012 and included regular thermal, gas, and ash emissions with occasional lava fountaining and pyroclastic flows. Activity peaked during 13-14 September 2012 with a VEI 3 (Volcanic Explosivity Index; where 3 is considered moderate (Newhall and Self, 1982)) summit eruption and SW-directed pyroclastic flow.

During this reporting period, continuous monitoring efforts by the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) included seismic monitoring, regular ground-based observations, and field visits. The Washington Volcanic Ash Advisory Center (VAAC) regularly included monitoring data from INSIVUMEH with satellite remote sensing emissions announcements. We also summarize a recent international collaboration between INSIVUMEH and the International Volcano Monitoring Fund (IVM-Fund) during 2010-2013.

Local observers reported ashfall, shockwaves, and lahars. According to INSIVUMEH, during 2011-2013, ashfall and explosive sounds were frequently reported by communities located within the W sector and up to 8 km of Fuego’s summit. Lahars occurred on the S-sector flank in the Taniluyá, Ceniza, Santa Teresa, Las Lajas, and Trinidad drainages (figure 16). Those drainages were also hazardous due to channelization of pyroclastic flows, block avalanches, and lava flows (figure 17); significant events occurred in mid-to-late 2012 and February 2013 (described later in this report). On the SE flank, Las Lajas was frequently affected by pyroclastic flows, and the drainages Taniluyá and Ceniza (SW flank) occasionally contained active lava flows and block avalanches.

Figure 16. This location map includes villages (numbered), observation sites in Panimaché I (FO-1) and Sangre de Cristo (FO-2), and primary drainages located within 15 km of Fuego’s summit vent (red star). Elevation contours are shown for 100 m intervals. Pyroclastic flow deposits from 13 September 2012 are shown as dark gray areas within Ceniza, Trinidad, El Jute, and Las Lajas drainages. Courtesy of Rüdiger Escobar-Wolf (Michigan Technological University).
Figure 17. This annotated photograph is centered on Fuego’s SW flank, the location of the Ceniza drainage, which channeled the major pyroclastic flow of 13 September 2012. The yellow dotted line marks the centerline of the pyroclastic flow; the orange lines enclose the region burned and scoured by ash cloud surges. Courtesy of INSIVUMEH.

Thermal anomaly detection during 2011-2013. Hotspots from the summit region were detected by satellite remote sensing instruments including MODIS (onboard the Terra and Aqua satellites), Landsat 7, and EO-1 Advanced Land Imaging (ALI) throughout this reporting period.

The MODVOLC thermal alert system recorded ~90 significant anomalies between 1 January 2011 and 1 January 2012, ~375 between 1 January 2012 and 1 January 2013 when explosive activity escalated, and ~255 between 1 January 2013 and 31 March 2013 when lava flows were active near the summit region (figure 18). Thermal anomalies were detected by satellite images at least once per month from January 2011 through March 2013 except for July 2011, suggesting poor weather may have inhibited satellite observations that month (note that heaviest rainfall typically occurs during June-October (The World Bank, 2013)). During July 2011, ground-based observations of nighttime incandescence were noted in INSIVUMEH’s Report # 1863; other reports that month highlighted the effects of heavy rain from tropical storms and Hurricane Calvin.

Figure 18. During 1 January 2011-31 March 2013, the MODVOLC system frequently detected elevated temperatures in the area of Fuego’s summit. This series of images includes hotspots detected during three time periods: 2011, 2012, and 1 January-31 March 2013. Courtesy of the Hawai`i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System.

MODVOLC continued to detect hotspots during late April 2013 totaling 22 pixels during 21-28 April. Thermal anomalies became rare during May and June 2013; one pixel was detected on three different days.

Regular images captured by ALI and Landsat 7 detected variable incandescence from Fuego’s summit during 2011-2013 (figure 19). During 2011, hotspots were mainly located at Fuego’s summit; however, during March and December, distinctively elongate, incandescent lava flows extended from the summit to the SW (figure 19A and 19B).

Figure 19. Satellite images from 2011-2013 detected incandescence from Fuego’s summit area. (A) This ALI image from 3 February 2011 showed a small region of incandescence isolated at the summit. (B) A Landsat 7 image from 7 November 2011 revealed a ~300 m incandescent flow originating from the summit and extending down the SW flank. (C) This Landsat 7 image from 4 September 2012 (nine days before the VEI 3 eruption began) captures intense incandescence that extends in three directions from the summit; some image distortion is present from cloudcover and artifact stripes (on the left-hand side). Distinctive yellow regions indicate lava reaching at least 500 m SE and SW. (D) This ALI image from 20 March 2013 captures a lava flow extending ~1,500 m SW from the summit crater within the upper region of the Ceniza drainage; some cloudcover blocks the middle region of the lava flow, but the red glow is visible and especially bright at the termination point SW of the clouds. Image processing by Rüdiger Escobar-Wolf (Michigan Technological University); courtesy of NASA/USGS.

Summit incandescence extending SW, SE, and in the immediate summit area was visible during 2012; some of the strongest incandescence extended at least 1 km from the summit to the SW during November-December. Incandescent flows directed SE appeared in April, June, and September. On 4 September 2012, three narrow flows were visible from the summit extending ≥ 500 m from the summit within the S sector; despite significant cloudcover that day and image artifacts, the lava flows were well-defined (figure 19C).

Satellite images from December 2012 through January 2013 included a long lava flow that persisted in the SW drainage (Ceniza), although cloudcover frequently obscured the full view of Fuego’s SW quadrant. That incandescent lava flow remained visible in satellite images until late February 2013. Incandescence was isolated at the summit in early March, but on 20 March incandescence re-appeared within the Ceniza drainage and extended ~2,000 m SW of the summit (figure 19D).

Effusive activity during 2011-2013. The style of eruptive activity at Fuego changed near the end of 2010 when lava effusion events started to occur more frequently than explosive eruptions (figure 20). “At a very general level, the more Strombolian eruptions happen typically during lava effusion times and are much smaller than the more Vulcanian eruptions,” commented Rüdiger Escobar-Wolf (Michigan Technological University) with respect to Fuego’s more than 12 year-long eruption. Continuous unrest (background-level explosions and effusion) was frequently punctuated by short periods of elevated activity during the preceding six years and, during 2012 and 2013, this activity was interrupted by several significant episodes: in 2012, 25-26 May; 10-11 June; 3-4 and 13-14 September; and in 2013, 17-18 February; 3-4 and 19-20 March (figure 19D).

Figure 20. Fuego time series from late 1999 to early 2013 with color codes indicating eruption style (Escobar-Wolf, 2013). Beginning in 1999, the eruption mainly consisted of periods of explosive events (color coded as green) and lava effusion (coded as gray); this constant unrest is considered background activity that has been occasionally interrupted with significant episodes (red lines). This timeline was created and provided by Rüdiger Escobar-Wolf, Michigan Technological University.

The Washington VAAC released an increasing number of notices for the aviation community about volcanic ash throughout 2011- March 2013 (table 8). During 2011, these announcements rarely contained calculated plume altitudes due to poor viewing conditions with satellite remote sensing. Data from INSIVUMEH supplemented these reports with direct observations from Fuego Volcano Observatory, located in Panimaché, 8 km SW of Fuego. On 1 January, 8 January, 23 October, and 24 December 2011, reported plume altitudes were less than 5.2 km a.s.l. and had drift speeds in the range of 2.5-10 m/s, drifting S and SW of Fuego's peak.

Table 8. The Washington VAAC released regular advisories due to emissions from Fuego during 2011-March 2013. Date, time, altitude, drift direction, and reporting sources are included as well as comments that described additional eruption characteristics such as thermal anomalies and weather conditions that may have affected observations. Drift velocities and plume width were also calculated when viewing conditions were optimal. INSIVUMEH was a frequent contributor to these reports; other reporting sources included the satellite GOES-2 (NOAA geostationary weather satellite), MWO (local Meteorological Watch Office), Guatemala City's (MGGT) meteorological reports (METAR), and the global numerical weather prediction models GFS and NAM. Courtesy of Washington VAAC.

DATE - TIME
(UTC)
ALTITUDE
(km)
DRIFT DIRECTIONVAAC SOURCESCOMMENTS
01 Jan 2011 - 1515 5.2 9 km wide line; W 10 m/s GOES-13. GFS WINDS. Several small emissions.
08 Jan 2011 - 1015 5.2 18.5 km wide plume; SW 2.6-5 m/s GOES-13. GFS WINDS. Multiple exhalations since 08/0600 UTC; these explosions have been seen in satellite before dissipating.
13 Feb 2011 - 0504 GOES-13. INSIVUMEH. INSIVUMEH reported increased activity within the summit area; low height emissions of volcanic ash moving W; hot spot was also detected in short wave infrared imagery.
14 Feb 2011 - 0427 GOES-13. INSIVUMEH. INSIVUMEH continued to report low levels of volcanic ash near the summit.
15 Feb 2011 - 0427 GOES-13. INSIVUMEH. Only steam reported.
23 Oct 2011 - 1327 GOES-13. Information received about a possible volcanic ash eruption.
23 Oct 2011 - 1245 4.3 W 2.6-5 m/s GOES-13. GFS WINDS. Confidence in height of volcanic ash is medium-high based on movement and density of ash in models and satellite imagery.
22 Nov 2011 - 1530 GOES-13. INSIVUMEH. Ash observed at 1530 UTC.
22 Nov 2011 - 1745 Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH observed thin plume of possible ash moving SW at 5 m/s at 1530 UTC. This weak plume was observed in satellite imagery at 1415 UTC but had dissipated by 1545 UTC.
02 Dec 2011 - 1845 Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported emission of gases near the summit and light ash that was too small to see in clear satellite imagery. Ash was reported to 305 m above the summit and dispersing SW around 18.5 km.
06 Dec 2011 - 1845 GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported volcanic ash cloud to 3 km observed at 1600 UTC. No ash was observed in satellite imagery.
24 Dec 2011 - 1904 GOES-13. INSIVUMEH SEISMIC DETECTION. Small narrow plume of unknown content began around 1645 UTC; VAAC received information suggesting a possible ash eruption.
24 Dec 2011 - 1845 4 5.6 km wide line; S 2.5 m/s GOES-13. INSIVUMEH SEISMIC DETECTION. Small plume of gases with possible ash extended 9 km; small puff seen in visible imagery started around 1645 UTC and drifted S 2.5 m/s; estimated height 4 km a.s.l. with wind forecast uncertain. Plume was projected to dissipate within 6 hours.
25 Dec 2011 - 0015 GOES-13. A possible eruption at 1845 UTC; ash not identifiable in satellite imagery; there were no reports of ash.
03 Jan 2012 - 2041 GOES-13. Possible volcanic ash detected in visible imagery at 2015 UTC moving SE.
03 Jan 2012 - 2045 5 3.7 km wide line; S 2.6 - 5 m/s GOES-13. GFS WINDS. INSIVUMEH. Small puff seen in visible imagery at 5 km a.s.l. moving SE 3.5 m/s. At 2045 UTC the leading edge was 12 km SE of summit and dispersing. Plume was projected to dissipate within 6 hours.
16 Jan 2012 - 1724 xx xx INSIVUMEH. The VAAC received information suggesting a possible volcanic ash emission.
16 Jan 2012 - 1740 GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to 4.3 km; no ash seen in imagery through 1715 UTC with clear skies.
18 Jan 2012 - 1215 6.7 W at 5-7.5 m/s GOES-13. GFS WINDS. Visible and multi-spectral imagery showed a single puff of gas and ash moving W from the summit; ash was projected to dissipate within a few hours as it continued W. A hotspot was detected.
01 Feb 2012 - 1645 GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to ~5 km at 01/1600 UTC; ash not observed in satellite imagery even with sparse clouds.
01 Apr 2012 - 1315 5 9.3 km wide line; SW 2.6-5 m/s  GOES-13. GFS WINDS. NAM WINDS. Plume extended 13 km WSW from the summit; well-defined hotspot seen in imagery; forecast confidence was low based on latest GFS and NAM.
19 May 2012 - 0915 GOES-13. GFS WINDS. INSIVUMEH. Ash was not seen in satellite imagery due to darkness; hotspot was visible; INSIVUMEH reported volcanic ash up to 5.5 km a.s.l. to 40 km SW of the summit.
19 May 2012 - 1515 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. INSIVUMEH Photos. Ash was not seen in satellite imagery due to cloudcover; a strong hotspot was visible in satellite multispectral imagery; seismicity was high.
19 May 2012 - 2045 GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Volcanic ash was not detected in satellite imagery due to extensive cloud cover; INSIVUMEH indicated pyroclastic flows likely and ashfalls have been observed.
20 May 2012 - 0245 GOES-13. GFS WINDS. Ash was not observed in satellite imagery due to cloudcover; hotspot had decreased in intensity and late afternoon bulletin indicated decreased energy.
20 May 2012 - 1415 GOES-13. NAM WINDS. INSIVUMEH. No ash was observed in imagery although there were thick clouds in the area; INSIVUMEH reported ash emissions up to 3,000 m above the summit moving SW.
20 May 2012 - 1945 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash was seen in imagery due to cloudcover; seismic signal has almost gone to background but with very occasional bursts that may contain volcanic ash.
21 May 2012 - 0045 GOES-13. GFS WINDS. INSIVUMEH. No volcanic ash detected due to cloudcover; INSIVUMEH's evening report only mentioned occasional emission of ash to 4 km a.s.l. or just above the crater drifting SW and dispersed within 9.3 km; seismic activity was back to normal with only occasional small bursts.
25 May 2012 - 1542 GOES-13. INSIVUMEH. Eruption of lava began around 1300 UTC; some volcanic ash was possible.
25 May 2012 - 1615 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. METAR. Pilot Report. INSIVUMEH. No plume was seen in satellite imagery due to partly cloudy conditions; pilot report of ash to 7 km a.s.l. moving SW; lava flows generated volcanic ash and gas; no explosive eruption seen in the seismic records; ash was forecasted to moving SW; a strong hotspot was visible in satellite imagery.
26 May 2012 - 0415 GOES-13. GFS WINDS. Volcanic ash was not detected in satellite imagery due to extensive cloudcover; INSIVUMEH indicated constant pyroclastic flows and reports of ashfall.
26 May 2012 - 1015 GOES-13. GFS WINDS. SEISMIC
DETECTION.
Volcanic ash was not seen due to darkness and weather conditions; strong hot spot was visible in satellite imagery and seismic activity remained elevated.
26 May 2012 - 1615 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash was not seen in imagery due to cloud cover; INSIVUMEH indicated that ash and gas emissions continued.
26 May 2012 - 2215 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash was not seen in satellite imagery due to cloudcover; INSIVUMEH reported decreasing seismicity; a hot spot persisted in multispectral imagery.
27 May 2012 - 0415 GOES-13. INSIVUMEH. INSIVUMEH indicated ongoing lava flows; decreasing seismic activity and no mention of ashfall in the most recent report.
05 Jun 2012 - 1732 GOES-13. INSIVUMEH. INSIVUMEH reported increasing activity and suggested that an explosive eruption with little or no warning was possible; hot spot was seen in satellite imagery but no volcanic ash due to cloud cover.
06 Jun 2012 - 1729 GOES-13. INSIVUMEH. INSIVUMEH reported intermittent explosions expelling ash and gas up to ~600 m above the summit; they warned that an explosive eruption with little or no warning was possible.
07 Jun 2012 - 1715 GOES-13. INSIVUMEH. INSIVUMEH reported activity that was limited to within 11 km of the summit; no ash was visible in satellite imagery due to partly cloudy conditions.
11 Jun 2012 - 0945 Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. No ash seen in satellite imagery due to nighttime darkness; hotspots see for last few hours. INSIVUMEH reported ash to 5 km.
11 Jun 2012 - 1545 GOES-13. INSIVUMEH. No ash was seen in imagery although there was some cloudcover; there was a strong hotspot occasionally seen in shortwave imagery; INSIVUMEH reported continuous ash emissions up to 15 km to the W and WNW of volcano.
21 Jun 2012 - 1552 Tegucigalpa MWO. GOES-13.
GEOPHYSICAL INST. EMAILED PHOTOS.
No ash detected due to cloudcover; INSIVUMEH reported ash moving E from rockfalls and aided by heat of lava flows; bit hotspots were visible through clouds.
21 Jun 2012 - 2138 GOES-13. GFS WINDS. No ash detected in visible satellite imagery due to cloudcover; hotspot seen in infrared imagery.
22 Jun 2012 - 0340 GOES-13. GFS WINDS. No ash seen in visible or multispectral satellite imagery due to night time darkness and cloudcover; hotspot observed prior to clouds moving in 22/0015 UTC.
03 Sep 2012 - 1415 4.3/5.2 5.6 km wide line; SW 5-7.5 m/s
7.4 km wide line; W 2.6-5 m/s
GOES-13. GFS WINDS. Ash plume height confidence is medium, the estimation is based on models and history of volcanic activity; a well-defined hotspot was seen overnight.
03 Sept 2012 - 2015 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Due to clouds, no good detection of ash but before the clouds arrived, faint ash was seen W-SW as far as 27.7 km; strong hotspots due to lava flows and rockfalls.
04 Sep 2012 - 0145 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash detected due to clouds and darkness; multiple hotspots were seen due to rockfalls and lava flows; some ashfall was reported SW of the summit up to 13 km.
04 Sep 2012 - 0445 4.5 W 2.6-5 m/s GOES-12. GFS WINDS. INSIVUMEH SEISMIC DETECTION. A plume was visible in multispectral imagery extending about ~145 km W of the summit.
04 Sep 2012 - 1015 4.5 W 2.6-5 m/s GOES-13. A continuous emission of ash was visible in multispectral imagery extending ~145 km W of volcano; large hotspot was detected by shortwave imagery.
04 Sep 2012 - 1615 GOES-13. GFS WINDS. INSIVUMEH. Ash was not seen due to weather conditions; strong hotspot remains in thermal imagery and INSIVUMEH reported elevated seismic activity.
04 Sep 2012 - 2145 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash or hotspots detected due to thick clouds; INSIVUMEH reported continued lava flows and rockfalls that generated ash to ~4.5 km a.s.l. moving SW; ashfall was reported up to 15 m SW and W of the summit.
05 Sep 2012 - 1545 GOES-13. INSIVUMEH. Ash not seen in the satellite imagery due to partly cloudy skies; a faint hotspot was visible in the morning; INSIVUMEH confirmed that no ash emissions were detected.
13 Sep 2012 - 1115 5 W 7.5 m/s GOES-13. GFS WINDS. INSIVUMEH. Faint plume was detected with multispectral imagery that extended ~111 km W; INSIVUMEH reported ash up to 1,000 m above the summit and moving W and SW.
13 Sep 2012 - 1602 4.5 /6.7 SW 7.5 m/s / SW 7.5-10 m/s GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported new emission to 3,000 m above the summit W and SW of the summit. 13/1602 UTC image showed a dense ash plume spreading W and SW. Imagery through 13/1632 UTC showed dense volcanic ash emissions continuing.
13 Sep 2012 - 2045 7.3 W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Ash plume was 148 km wide and extended 226 km W of summit; ash was reported at MGGT METAR station.
14 Sep 2012 - 0045 7.3 W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Ash plume was 111 km wide and extended 417 W of the summit; ash closest to summit was obscured by cloudcover and was likely rained out; METAR from MGGT continued to report ash.
14 Sep 2012 - 0710 4.3 /7.3 W 5 m/s / W 5 m/s GOES-13. GFS WINDS. INSIVUMEH. A bright hotspot persisted with a small plume in multispectral imagery extending 36 km to the W of the summit; latest report indicated current activity was more intermittent and lower in height; larger area to 7.3 km a.s.l. continued to dissipate about 648 km to W of summit moving W.
14 Sep 2012 - 1245 4 /7.3 W 7.5-10 m/s / W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Multispectral imagery showed dissipating ash to 7.3 km a.s.l. between 370 km and 926 km W moving W; in addition, continuous attached plume to 4 km a.s.l. was seen moving SW; local surface observations reported 4 km a.s.l.
14 Sep 2012 - 1845 6 W 10 m/s GOES-13. GFS WINDS. INSIVUMEH. A dissipating area of ash, about ~1,000 km W of the summit, was detected in multispectral imagery; no ash was seen near the summit at 1845 UTC; INSIVUMEH reported ash emissions within 15 km of the summit.
15 Sep 2012 - 0045 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash was detected in satellite imagery; the previous plume located S of Mexico had dispersed around 14/2200 UTC. INSIVUMEH reported weaker seismic activity with rockfalls generating ash plumes to 4 km a.s.l. and 15 km W-SW of the summit; a strong hotspot was visible.
29 Sep 2012 - 1245 GFS WINDS. GOES-14. INSIVUMEH. In the morning, satellite imagery detected discreet puffs of ash moving W and WSW from the summit; INSIVUMEH reported ash 500 m to 900 m above the summit with fine ashfall.
17 Feb 2013 - 0544 GOES-13. INSIVUMEH. INSIVUMEH reports incredible outpouring of lava from the crater which is confirmed by brilliant hot spot in satellite imagery; INSIVUMEH reported no ash plume at the moment, but emissions are possible over the next few hours up to 10 km to the S and SW of the summit.
17 Feb 2013 - 1315 5 W 2.6-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. In the morning, visible imagery showed a plume of ash extending 18.5 km to the W of the volcano; INSIVUMEH reported ash to 4.8 km a.s.l.
17 Feb 2013 - 1445 5 W Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. Imagery showed ash moving W-SW and S from the volcano; at 17/1445 UTC ash extended 18.5 km SW and 5.6 km S of the volcano.
17 Feb 2013 - 2015 5.2 0-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions of lava with gas and light ash; in imagery the ash is mixed with clouds and, due to light winds spreading N-W-SW from the summit ~13 km; this is mainly a lava event but some light ashfall was being reported in cities on the slopes of the volcano.
18 Feb 2013 - 0815 GOES-13. GFS WINDS. INSIVUMEH. Ongoing lava emission with gases and light ash; no ash detected due to large thunderstorm that developed SW of summit and regional cloudcover. INSIVUMEH reported in the afternoon that less energetic lava, gas, and ash events were occurring.
03 Mar 2013 - 2345 GOES-13. GFS WINDS. INSIVUMEH. Lava emission with occasional light ash due to rockfalls and small venting; hotspot due to lava but no ash was visible in satellite imagery; plume drifted up to 9 km according to INSIVUMEH; wind forecast was light and variable, so the plume was expected to remain close to the summit region.
04 Mar 2013 - 0334 GOES-13. GFS WINDS. INSIVUMEH. An INSIVUMEH special report indicated that a new stage of emissions began and possible ash fall was likely around 18.5 km from the summit. Ash was not seen in multispectral satellite imagery; a very large hotspot was observed with infrared.
04 Mar 2013 - 0845 GOES-13. GFS WINDS. Ash was not seen in overnight satellite imagery; very large and bright hotspot was detected with infrared sensors; emissions of gas and ash were likely.
04 Mar 2013 - 1315 4.3 moving NE 5-7.5 m/s GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; satellite imagery showed a faint ash plume 13 km wide and extending 42.5 km NE of the summit; a very bright hot spot was detected with infrared sensors.
04 Mar 2013 - 1915 GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; ash was too light to be seen in visible satellite imagery although reports indicate that ash was present; a strong hot spot persisted.
05 Mar 2013 - 0115 Tegucigalpa MWO. GOES-13. Ongoing activity; Tegucigalpa MWO canceled Sigmet for the event; a well-defined hotspot was visible in multi-spectral imagery; no ash was present in the last visible images of the day.
18 Mar 2013 - 1345 4.3 moving SW 2.6-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. Very light volcanic ash emissions; MWO indicated ash moving SW; the ash had a SSW component in satellite imagery and was very light in nature.
18 Mar 2013 - 1945 GOES-13. GFS WINDS. INSIVUMEH. Emissions of gas and occasional light ash were near the summit; no ash was detected or reported in cloudy conditions; INSIVUMEH reported near-summit emissions of gas and occasional, very light ash below 4.3 km a.s.l. and within 9 km of the summit.
19 Mar 2013 - 2232 GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to 5 km a.s.l. at 19/2045 UTC moving SE at 5 m/s; ash not visible in imagery; special observatory report indicated elevated activity with the volcano; a persistent hotspot was present since 1915 UTC and had become increasingly bright in the past hour.
20 Mar 2013 - 0415 GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash plume was not identifiable in multispectral satellite imagery; a bright hotspot was detected with infrared sensors; occasional bursts of seismic activity were reported; SIGMET reports ash to 5 km a.s.l. moving SE at 5 m/s.
20 Mar 2013 - 1015 GOES-13. GFS WINDS. Near summit emissions of gases and occasional light volcanic ash; although brilliant hot spot was readily apparent in satellite imagery, no ash was detected under partly cloudy conditions.
21 Mar 2013 - 1332 5.5 E 7.5 m/s GOES-13. GFS WINDS. Intermittent emissions; ash emissions and a persistent hotspot were observed in satellite imagery in clear skies; several discreet puffs were noted; ash plume extends ~32 km to the ESE of the volcano.
28 Mar 2013 - 1315 4.6 W 2.6 - 5 m/s GOES-13. INSIVUMEH. ECMWF HIRES WINDS. Continuous emissions; a series of emissions has resulted in an ash plume extending up to 18.5 km to the WSW of the summit.
30 Mar 2013 - 1415 5 S 8 m/s GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. INSIVUMEH reported degassing with occasional bursts of ash at 1240 UTC, 1330 UTC, and 1415 UTC; multibursts of gas and ash seen moving to S and SE from the summit extending 55.5 km from the summit and dispersing; light ashfall was reported within 18.5 km of the summit.
30 Mar 2013 - 1945; 5 S 2.6-5 m/s GOES-13. GFS WINDS. Ongoing emissions; satellite imagery showed a 20 km wide plume of light ash extending 13 km S of the summit; ash was expected to disperse within 6 hours.
31 Mar 2013 - 1345 GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; ash not seen in satellite imagery under clear skies; however, sun may be preventing light ash from being observed; ash had been reported in the village of Panimaché.
31 Mar 2013 - 1945 GOES-13. GFS WINDS. INSIVUMEH. Continuous gas emissions with occasional short bursts of light ash; INSIVUMEH reported continued gas emissions with short bursts of light ash moving S; ashfall was reported within 9.3 km of the summit; ash not seen in satellite imagery due to cloud cover around the summit.

During 2011, INSIVUMEH reported that Fuego’s activity included small-scale explosions and effusive lava flows. Lava flow activity was reported mainly during late March, late April, June, and early July.  The longest lava flows traveled SW within the Ceniza and Santa Teresa drainages. Maximum flow lengths were in the range of 100-200 m and were frequently incandescent at night during spalling events.

Escalating summit activity during 2012. In early 2012, three VAAC advisories included plume altitudes as high as 6.7 km a.s.l. and drift directions up to 7.5 m/s S, SW, and W (table 8). INSIVUMEH reported that during the first week of January 2012, the Alert Level was raised to Yellow due to elevated activity; incandescent explosions were observed during 18-19 and 23 January. Lava flows and intermittent incandescent spatter continued from the summit throughout the rest of this reporting period (2011-March 2013).

The Coordinadora Nacional para la Reducción de Desastres  (CONRED) announced Alert Level Orange (third highest on a four-color scale) and evacuations from El Porvenir in Alotenango (9 km ENE) on 19 May due to escalating activity (figure 21). Energetic Strombolian eruptions occurred during 19-20 and 25-27 May. Pyroclastic flows during 25-26 May were directed E and SE (impacting the Las Lajas and El Jute drainages), unlike previous events that concentrated flows within the W sector. Significant populations, resorts, and infrastructure such as the RN-14 road are located along the Las Lajas and El Jute drainages.

Figure 21. A plot of the daily average RSAM (Real-time Seismic-Amplitude Measurement) from Fuego’s seismic station FG3 during January through September 2012. Notable peaks include eruptions during 19-20, 26-27 May and 11 June; the effusive eruption of 1 July; the 3 September eruption, lahars, and lava flows; and the 13 September eruption.  During this time period, seismicity was dominated by long-period (LP) earthquakes generated by processes such as explosions, fluid movement, lava flows, and block avalanches. Courtesy of INSIVUMEH.

During May-June, there were ~20 VAAC advisories that highlighted INSIVUMEH observations and the possibility of ash plumes; satellite observations and calculations of plume altitudes, however, were not available (table 8). INSIVUMEH reported lava flows throughout May-August (extending up to 1.7 km from the summit and as wide as 25 m) and pyroclastic flows occurred during May.

Increased explosivity at Fuego during September 2012. During the first week of September 2012, the Washington VAAC issued advisories describing ash plumes up to 5.2 km a.s.l. (table 8). A large event, on 3 September, generated two ash plumes dispersing SW and W, the former was ~5.5 km wide, and the latter was ~7.5 km wide. Ash plumes and hot spots continued to be visible within satellite images through 4 September (figure 19C) with INSIVUMEH reporting a lack of ash clouds on 5 September, followed by a break in reports until the major eruption on 13 September.

Beginning at 0400 on 13 September, a significant eruption occurred which led to evacuations from local communities within a 10-km radius (figures 22 and 23). At 0715, a vertical plume erupted from the summit. Large pyroclastic flows were generated between 0900 and 1000 local time which became channelized within two drainages. Within the Las Lajas drainage (on the SE flank), flows reached as far as 2 km from the summit; within the Ceniza drainage (SSW flank), they traveled as far as 7.7 km, stopping just 3 km short of Panimaché. On 14 September, the Washington VAAC reported ash plumes up to 7.3 km a.s.l. that drifted W at ~10 m/s (table 8).

Figure 22. On 13 September 2012, a large plume of ash erupted from Fuego and pyroclastic flows descended the flanks. Between 0900 and 1000 local time, a lateral cloud and a tall plume expanded from the summit. The sharp peak to the right of Fuego is Agua volcano.  This photo was taken from a viewpoint near the base of Pacaya volcano, ~30 km S of Guatemala City. Photo courtesy of Kent Caldwell.
Figure 23. Comparison views of Fuego made from the city of Antigua (~18 km from Fuego) looking SW. (Top) This view from the center of Antigua, was taken on 21 March 2008 at 0915 when volcanic unrest was dominated by intermittent, impulsive eruptions which generated short gas-and-ash plumes (see figure 20 for the timeline of explosive vs. effusive activity). Photo courtesy of Kyle Brill (Michigan Technological University). (Bottom) This photo taken at ~0900 on 13 September 2012 captures a view SW of the ongoing explosive eruption that continued through 14 September. Photo courtesy of Luis Echeverria (Xinhua Press/Corbis).

In a special report by INSIVUMEH, the 13-14 September 2013 eruption was described as the largest explosive event within the last 13 years; they assigned the event VEI 3 (Volcanic Explosivity Index) based on the volume of pyroclastic material. This was the first eruption since 1974 that directly impacted the S and SW zones of Fuego, areas within 5-7 km of the summit that contained numerous small villages (figure 24). Approximately 10,600 people were evacuated from Panimaché I, Panimaché II, Sangre de Cristo, Morelia, and El Porvenir (figure 16) to the town of Santa Lucía Cotzumalguapa (18 km SW). INSIVUMEH estimated that ~5 mm of ashfall accumulated in those regions closest to the channelized pyroclastic flows. Ashfall damaged coffee and other agricultural crops in the region and congested the air, decreasing visibility in many communities within 10 km of the summit.

Figure 24. Two hybrid graphics each merging a regional map and MODIS image centered on Fuego (at the red pushpin icon). (A) Results captured at 1030 local time showing a plume generated by the eruption covered approximately ~900 km2. (B) At 1330 local time, the ash plume covered approximately ~2,500 km2, with less density; 47 municipalities in seven departments were primarily affected. The ash extends off this graphic and later reached Chiapas, Mexico. Image modified from CATHALAC, 2012.

Prior to the eruption, there wsa a notable increase in LP seismicity and high-amplitude tremor that lasted for hours. INSIVUMEH seismic records became saturated between 0947 and 0949, the time period when observers noted ash plumes rising from the summit (figure 7). During the explosive event that began at 0400 on 13 September 2012, a lava flow advanced 300 m down the flank from the S side of the summit crater. At roughly the same time, a vertical plume rose from the crater and drifted SW; strong ENE winds rapidly spread the ash into the coastal Suchitepéquez Department. At 0715 the ash plume had risen up to 2 km above the summit crater; by 1500 that day, a diffuse ash plume was reported over the S region Mexico’s Chiapas Province. The ash continued to expand W and NW on 14 September, and was ~100 km wide and more than 415 km W of the summit (table 8 and figure 10); ash persisted in the atmosphere for more than 36 hours.

Figure 25. A large ash plume drifted W and NW from Fuego on 14 September 2012; observations were made at 0045, 0700; 1300; and 1900 local time and remote sensing measurements determined an altitude of ~7 km a.s.l. These graphics notified the aviation community about airspace containing ash plumes. Note that “VA to FL 240” means “volcanic ash to flight level 24,000 (~7 km).” Courtesy of Washington VAAC.

Seismicity and surface activity returned to low levels after the powerful 13-14 September 2012 eruption. Field studies conducted by INSIVUMEH determined that the Las Lajas, El Jute, Trinidad, and Ceniza drainages received the largest concentration of volcanic material during the eruption, making these regions susceptible to lahars with the onset of the rainy season.

Within the Ceniza drainage, in particular, pyroclastic flows had extended ~8 km (figures 17 and 26) and had deposited tree branches and trunks (many that were charred) within the canyon along with large (1-3 m diameter) blocks and volcanic bombs. Preliminary assessments of the deposits within the Ceniza drainage determined that ~13,000,000 m3 of material had been deposited and was already becoming mobilized.

Figure 26. During field investigations immediately after the 13 September 2012 eruption, INSIVUMEH surveyed the Ceniza drainage to assess both the damage and potential new hazards from lahars. This area sits in the region of Siquinala and San Andrés Osuna, ~13 km SSW of Fuego’s summit. Courtesy of INSIVUMEH.

Assessments by INSIVUMEH at the end of 2012 determined that two months of heavy rain had cut deep incisions into the new deposits and that loose, fine-grained volcaniclastic material had already migrated down to the road crossing at Siquinala and San Andrés Osuna, ~13 km SSW of the summit. The study also described the increased vulnerability of the road access for Siquinala and the community of La Róchela (figure 16) due to possible stream capture by Ceniza with Platanares. A narrow (~15 m) zone of the Ceniza drainage had been filled with volcaniclastic material, changing the drainage profile in a location ~2 km upstream from an important stream crossing. The Ceniza drainage had been migrating laterally toward the Platanares over time, especially due to erosion following Tropical Storm Agatha in 2010.

Explosive and effusive activity continued during September 2012-March 2013.From late September 2012 through March 2013, INSIVUMEH documented ash plumes (100-1,300 m above the crater), incandescent spatter (50-200 m above the crater), lava flows (mainly flowing 100-900 m down the SW flank), and lahars.  In 2012, hot lahars were reported on 1 June, and later on 27 September and 3 October. Lava flows were frequently channelized within the Ceniza, Trinidad, and Taniluya drainages (SW flank). The last significant VAAC report of 2012 highlighted discreet puffs of ash that reached a maximum of 900 m above the crater on 29 September (table 8).

Large pyroclastic flows on 16 and 17 February 2013 traveled 3 km down the Ceniza drainage (table 8). Ash plumes generated on 16 February caused ashfall in communities up to 12 km from the summit, primarily SW. On 17 February there were collapses at lava-flow fronts.

On 4 March 2013 there were large lava flows following incandescent explosions up to 100 m above the crater (table 8).

On 19 March an explosive eruption occurred with effusive lava flows; a ~5 km a.s.l. ash plume was detected by the Washington VAAC (table 8). Lava fountaining reported on 20 March rose 300-400 above the crater; a ~1.5 km long lava flow within the Ceniza drainage was also observed that day (figure 19D). Incandescent explosions were frequently observed through the rest of the month.

International collaboration aids monitoring capabilities in 2013. In 2010, a partnership was established between INSIVUMEH observatories and the International Volcano Monitoring Fund (IVM-Fund), a non-profit organization based in Seattle, WA. After a successful project to improve monitoring efforts at the Santiaguito Volcano Observatory (OVSAN), the IVM-Fund began working with the Fuego Volcano Observatory (OVFGO), located in Panimaché, in 2012. During March 2013, this observatory received significant support from the IVM-Fund and international donors.  Jeff Witter, president and CEO of the IVM-Fund, delivered ~$4,500 worth of field equipment to OVFGO to help outfit the observers and contribute to volcano monitoring capacity in Guatemala (figure 27). Additional visits to Guatemala are planned once sufficient funds are raised to continue the IVM-Fund's collaborative work with Guatemalan volcanologists. Volcano monitoring support projects between the IVM-Fund and INSIVUMEH are planned to address additional needs at OVFGO and OVSAN.

Figure 27. On 21 March 2013, INSIVUMEH technician Amilcar Cardenas (left) and Edgar Barrios (far side of river) measure the width of Taniluya drainage to collect baseline data for monitoring geomorphologic changes in the canyon. This drainage is particularly susceptible to lahars and pyroclastic flows. Courtesy of Jeff Witter (IVM-Fund).

References. CATHALAC, 2012, “Preliminary Analysis of the Eruption of Volcan de Fuego, Guatemala -- 13 September 2012,” posted on 27 September 2012, https://servirglobal.net/Global/Articles/tabid/86/Article/1169/preliminary-analysis-of-the-eruption-of-volcan-de-fuego-guatemala-13-september.aspx, accessed on 17 July 2013.

Escobar-Wolf, R., 2013, Volcanic processes and human exposure as elements to build a risk model for Volcán de Fuego, Guatemala [PhD Dissertation]: Houghton, MI, Michigan Technological University.

Newhall, C.G., and Self, S., 1982, The volcanic explosivity index (VEI): An estimate of explosive magnitude for historical volcanism, Journal of Geophysical Research: 87, 1231-1238.

The World Bank, 2013, Country Data: Guatemala Climate Change, http://data.worldbank.org/country/guatemala, accessed on 18 June 2013.

Information Contacts: Gustavo Chigna M., Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/inicio.html); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (URL: http://conred.gob.gt/www); Washington Volcanic Ash Advisory Center (VAAC), NOAA Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC); Rüdiger Escobar-Wolf, Michigan Technological University, Department of Geological and Mining Engineering and Science, Houghton, MI, USA (URL: http://www.geo.mtu.edu/); Hawai`i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System (MODVOLC), School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai`i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/); Jeff Witter, International Volcano Monitoring Fund (IVMF) (URL: http://www.ivm-fund.org/guatemala-fuego/); NASA/USGS Landsat Program (URL: https://landsat.usgs.gov/); and NASA ALI (URL: http://eo1.gsfc.nasa.gov/).

04/2014 (BGVN 39:04) Explosions, ash plumes, lava flows, and lahars during April 2013-June 2014

In this report we highlight Fuego's ongoing eruptive activity during April 2013-June 2014. During this reporting period continued monitoring by the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) included ground-based observations, field visits, and seismic monitoring. Aviation reports were abundant from the Washington Volcanic Ash Advisory Center (VAAC). The active summit crater was a frequent source of thermal alerts from the MODVOLC system which is based on infrared radiation detected in space by the MODIS instruments.

Advancing lava flows and ash explosions. INSIVUMEH reported that lava flows advanced from Fuego's summit during the entire reporting interval. By 29 June 2014, a lava flow was extending 150 m toward the TaniluyÁ drainage and generating avalanches that reached the Ceniza drainage. Earlier in the year, lava flows up to 550 m long reached vegetated areas on the SW flank.

INSIVUMEH and Washington VAAC reported frequent ash explosions from Fuego's summit crater during April 2013-June 2014 (figure 28). Ash plumes typically rose 100-800 m above the summit. Significant ash plumes drifted 10-20 km from the summit in the direction of prevailing winds. An exceptional case occurred when ash drifted 30 km NW during activity on 30 December 2013. Constant fumarolic activity generated diffuse, white plumes that rose approximately 150 m above the summit. Incandescent explosions were also frequently observed at night and reached 200 m above the summit (figure 29).

Figure 28. Two satellite images captured incandescence from Fuego on 18 January 2014 (top) and 4 December 2013 (bottom). (top) This EO-1 ALI image is the product of 3 bands: band 10 for thermal, band 9 for clouds, and band 4 for near-infrared. A small, round ash plume was also visible drifting NE of the summit. (bottom) This Landsat 8 image is a combination of visible and infrared bands (band 7 for near-infrared, band 6 for thermal infrared, and band 3 for chlorophyll absorption). Image processed by Rüdiger Escobar Wolf (Michigan Tech University) and acquired by NASA/USGS.
Figure 29. Comparisons of infrared video images with seismic traces for Fuego during 21-22 April 2014. These still views (A-C) enabled viewers to gauge the degree, timing, and correlation between major explosions accompanied by incandescence and seismic signals. The respective images coincide with the points along the seismic trace intersected with the heavy black vertical lines. Courtesy of Rüdiger Escobar Wolf (https://www.youtube.com/watch?v=mvGw7AUCtCo), INSIVUMEH, US-AID, and Michigan Tech University.

Figure 29 shows moderate-sized (~200-m-high) incandescent plumes occurring at the time of high-amplitude seismic signals (panels A and B) whereas minor explosions (panel C) produced little-to-no seismic signal (note that no significant seismicity occurred near the 10:20 tickmark). The Michigan Tech research team postulated that the lack of seismic signal in panel C is the result of the seismometer only registering the ground coupled airwaves during the sequence as opposed to the explosion signature (personal communication by Rüdiger Escobar-Wolf). Some of the explosions recorded during this time were heard in neighboring communities.

Shockwaves from explosions, rumbling from avalanches, and ashfall from explosive events were frequently reported by inhabitants from local communities (table 9). Windows and metal roofs rattled during major events and there were such numerous reports received by INSIVUMEH from residents within 10 km of the summit.

Table 9. Ashfall from explosions at Fuego was reported in numerous communities during 27 March 2013 - 19 June 2014. A map of town locations can be found in BGVN 36:06, figure 16. Courtesy of INSIVUMEH.

Year Date Town reporting ashfall
2013 27 March-2 April Panimaché I and II (8 km SW), Morelia (9 km SW), and Hagia Sophía
28 Jun. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
18 Nov. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
21 Nov. Sangre de Cristo (8 km WSW)
2014 3 Jan. Panimaché (8 km SW), Morelia (9 km SW), and Sofía I and II (12 km SW)
13 Jan. Panimaché (8 km SW), Morelia (9 km SW), and Sangre de Cristo (8 km WSW)
2 Feb. Panimaché (8 km SW), Morelia (9 km SW), and the W flank
25 Mar. Sangre de Cristo (8 km WSW) and surrounding areas
22-23 Mar. Santa Sofía (12 km SW), Panimaché I and II (8 km SW), Morelia (9 km SW)
10-11 Apr. Panimaché (8 km SW) and Sangre de Cristo (8 km WSW)
20-22 Apr. Panimaché (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW)
25-28 Apr. Panimaché (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW)
18-19 Jun. Within 15 km of the summit, mainly El Porvenir (8 km ENE), Los Yucales (12 km SW), Santa Sofía (12 km SW), Morelia (10 km SW), and Panimaché (I and II, ~8 km SW). Also, ashfall was reported in Sangre de Cristo (8 km WSW) on 18 June.

Thermal anomaly detection during 2013-2014. Except for June 2014, hotspots at the summit region were detected by satellite remote sensing instruments during each month of this reporting period (table 10). Platforms capturing the infrared data included MODIS (onboard the Terra and Aqua satellites), Landsat 8, and EO-1 Advanced Land Imaging (ALI).

Table 10. The MODVOLC system generated thermal alerts from Fuego during April 2013-May 2014. Courtesy of HIGP.

Year Month Day #Pixels/Day
2013 Apr. 14 2
Apr. 21 1
Apr. 23 1
Apr. 25 2
Apr. 26 3
Apr. 27 4
Apr. 28 9
May 9 1
Jun. 15 1
Jun. 17 1
Jul. 8 2
Jul. 10 2
Jul. 12 1
Jul. 15 1
Jul. 22 2
Jul. 26 1
Jul. 28 2
Jul. 29 1
Aug. 8 1
Aug. 9 1
Aug. 11 1
Aug. 15 2
Aug. 18 2
Aug. 19 1
Aug. 20 4
Aug. 23 1
Sept. 3 1
Sept. 14 1
Oct. 5 1
Oct. 11 2
Oct. 14 2
Nov. 4 4
Nov. 15 1
Nov. 18 1
Nov. 19 3
Nov. 20 2
Nov. 24 2
Nov. 27 1
Dec. 3 1
Dec. 5 1
Dec. 10 2
Dec. 15 5
Dec. 16 2
Dec. 28 2
Dec. 30 1
2014 Jan. 2 1
Jan. 5 1
Jan. 7 4
Jan. 11 1
Jan. 15 2
Jan. 18 5
Jan. 20 1
Jan. 22 1
Jan. 23 2
Jan. 25 5
Jan. 28 1
Jan. 29 2
Jan. 31 1
Feb. 2 1
Feb. 4 1
Feb. 5 5
Feb. 6 1
Feb. 7 1
Feb. 8 1
Feb. 12 1
Feb. 21 2
Feb. 24 1
Mar. 1 1
Mar. 5 1
Mar. 11 3
Mar. 20 1
Mar. 21 1
Mar. 23 4
Mar. 25 2
Mar. 27 1
Mar. 28 1
Mar. 29 1
Mar. 30 2
Apr. 1 1
Apr. 15 1
Apr. 16 1
Apr. 21 1
Apr. 22 1
Apr. 27 1
May 17 1
May 18 2
May 19 2

Lahar hazards. Drainages within the southern sector of Fuego were frequently at risk for lahars during 2013-2014. In particular, the rivers Las Lajas, El Jute, Honda, Seca, Ceniza, Santa Teresa, and TaniluyÁ were inundated by lahars during this reporting period (table 11). A map of river locations can be found in figure 7 of BGVN 30:08.

Table 11. During May 2013- June 2014, weak- to strong-flowing lahars from Fuego were frequently triggered by heavy rainfall, mainly during May-September (the rainy season) each year. Courtesy of INSIVUMEH.

Year Date Drainages Dimensions Load Damage/At risk
2014 9 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks na
5 Jun. Honda (E), El Jute (SE), Ceniza (SSW), & Santa Teresa (S) na 1.5 m diameter blocks na
2 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks na
1 Jun. Las Lajas (SE), Honda (E), & Seca (W) na na Traffic crossing the Río Seca was disrupted as well as the road crossing on the W and S sides
2013 11 Sept. Las Lajas & El Jute (SE) 30 m wide; 4 m deep 2 m diameter blocks; branches and tree trunks na
10 Sept. Taniluyá (SW) 15-20 m wide; 1-2 m deep Tree trunks Roads were blocked in Panimaché I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW) for two hours
9 Sept. Las Lajas & El Jute (SE) na 2 m diameter blocks na
17 Aug. Las Lajas, Ceniza (SSW), & El Jute (SE) 30 m wide blocks na
5 Jul. Las Lajas & El Jute (SE) na 0.5 m in diameter na
27 Jun. Las Lajas & El Jute (SE) na 1.5 m diameter blocks; branches and tree trunks na
8 Jun. Las Lajas (SE), El Jute (SE), &Ceniza (SSW) na na na
2 Jun. Ceniza (SSW) blocks; trees and logs na na
29 May Las Lajas & El Jute (SE) na 0.5 m in diameter na

Information Contacts: Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/inicio.html); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (URL: http://conred.gob.gt/www/); and Washington Volcanic Ash Advisory Center (VAAC), NOAA Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC).

Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2002 Jan 4 2014 Sep 16 (continuing) Confirmed 2 Historical Observations
1999 May 21 2000 Dec 9 (in or after) Confirmed 2 Historical Observations
1987 Jan 5 ± 4 days 1987 Feb (?) Confirmed 1 Historical Observations
1977 Sep 11 1979 Aug 8 Confirmed 2 Historical Observations
1977 Mar 3 1977 Apr 19 Confirmed 1 Historical Observations
1975 May 28 1975 Oct 21 Confirmed 1 Historical Observations
1974 Oct 10 1974 Dec 4 Confirmed 4 Historical Observations
1973 Feb 23 1973 Mar 23 Confirmed 2 Historical Observations
1971 Sep 14 1971 Sep 15 Confirmed 3 Historical Observations
1967 Apr 22 1967 Apr 24 Confirmed 2 Historical Observations
1966 Aug 12 1966 Aug 13 Confirmed 3 Historical Observations
1966 Feb 7 1966 May 1 Confirmed 3 Historical Observations
1963 Sep 28 1963 Sep 30 Confirmed 3 Historical Observations
1962 Aug 4 1962 Nov 9 Confirmed 3 Historical Observations
1957 Feb 19 1957 Feb 21 (in or after) Confirmed 3 Historical Observations
1955 Jul 26 ± 5 days Unknown Confirmed 1 Historical Observations
1953 Apr 9 1953 Apr 13 Confirmed 3 Historical Observations
1949 Nov Unknown Confirmed 2 Historical Observations
1947 Unknown Confirmed 2 Historical Observations
1944 Dec 1 ± 30 days Unknown Confirmed 2 Historical Observations
1932 Jan 21 1932 Jan 22 Confirmed 4 Historical Observations
1896 Jan 10 Unknown Confirmed 2 Historical Observations
1880 Jun 28 1880 Aug 20 Confirmed 4 Historical Observations
[ 1867 ] [ Unknown ] Uncertain 2  
[ 1861 Nov 21 ] [ Unknown ] Uncertain 2  
1860 Aug 18 1860 Sep 23 Confirmed 2 Historical Observations
1857 Sep 17 Unknown Confirmed 2 Historical Observations
1857 Jan 15 1857 Feb 17 Confirmed 4 Historical Observations
1856 Sep 29 1856 Sep 30 Confirmed 2 Historical Observations
1856 Jan 9 1856 Mar 7 Confirmed 2 Historical Observations
1855 Sep 29 1855 Sep 30 Confirmed 2 Historical Observations
[ 1852 ] [ Unknown ] Uncertain 2  
[ 1850 ] [ Unknown ] Uncertain 2  
1829 Unknown Confirmed 2 Historical Observations
1826 Unknown Confirmed 2 Historical Observations
1799 Unknown Confirmed 3 Historical Observations
[ 1773 ] [ Unknown ] Uncertain 2  
[ 1765 ] [ Unknown ] Uncertain 2  
[ 1751 ] [ Unknown ] Uncertain 2  
1737 Aug 27 1737 Sep 24 Confirmed 4 Historical Observations
1732 May Unknown Confirmed 2 Historical Observations
1730 Sep Unknown Confirmed 2 Historical Observations
1717 Aug 27 1717 Dec 26 ± 5 days Confirmed 4 Historical Observations
1710 Oct 14 Unknown Confirmed 2 Historical Observations
[ 1709 Oct 14 ] [ Unknown ] Uncertain    
1706 Oct 4 Unknown Confirmed 2 Historical Observations
1705 Jan 31 1705 Feb 2 Confirmed 2 Historical Observations
1702 Aug 4 Unknown Confirmed 2 Historical Observations
1699 Unknown Confirmed 2 Historical Observations
[ 1689 ] [ Unknown ] Uncertain 2  
1686 Unknown Confirmed 2 Historical Observations
1685 Sep Unknown Confirmed 2 Unknown Volcano Uncertain: pumice off Guatemala coast
[ 1679 ] [ Unknown ] Uncertain    
1629 1632 Confirmed 2 Historical Observations
1623 Jan Unknown Confirmed 2 Historical Observations
1620 Unknown Confirmed 2 Historical Observations
1617 Unknown Confirmed 3 Historical Observations
1614 Unknown Confirmed 2 Historical Observations
1587 Jul 24 Unknown Confirmed 2 Historical Observations
1586 Jun 3 ± 2 days 1586 Dec Confirmed 2 Historical Observations
1585 Jan 15 1585 Jul Confirmed 2 Historical Observations
1581 Dec 5 1582 Jan 15 Confirmed 4 Historical Observations
[ 1577 ] [ Unknown ] Uncertain 2  
[ 1576 ] [ Unknown ] Uncertain 2  
[ 1575 ] [ Unknown ] Uncertain 2  
[ 1571 Dec 25 ] [ Unknown ] Uncertain    
[ 1565 ] [ Unknown ] Uncertain 2  
[ 1559 Jan 16 ] [ Unknown ] Uncertain    
[ 1557 Jan 15 ] [ Unknown ] Uncertain    
1551 1552 Mar 31 (in or after) Confirmed 2 Historical Observations
1542 Jan 14 Unknown Confirmed   Historical Observations
1541 Unknown Confirmed   Unknown Volcano uncertain: possibly Atitlan
1531 Dec 31 ± 30 days Unknown Confirmed 2 Historical Observations
[ 1526 ] [ Unknown ] Uncertain 2  
1524 Apr 30 ± 30 days 1524 Jul 15 ± 45 days Confirmed 2 Historical Observations
0970 ± 50 years Unknown Confirmed   Radiocarbon (uncorrected)
0900 ± 75 years Unknown Confirmed   Radiocarbon (uncorrected)
0590 ± 75 years Unknown Confirmed   Radiocarbon (uncorrected)
1580 BCE ± 75 years Unknown Confirmed   Radiocarbon (uncorrected)

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Synonyms

Hunahpu

Cones

Feature Name Feature Type Elevation Latitude Longitude
Meseta Stratovolcano 3580 m 14° 29' 0" N 90° 53' 0" W
The Acatenango-Fuego complex is seen here from the NW. A steam plume drifts from the summit of Fuego (right), beyond the twin peaks of Acatenango (center). Like other N-S-trending volcanic chains in the Guatemalan highlands, activity at the Acatenango-Fuego chain migrated to the south. Yepocapa, the northernmost summit of Acatenango, was active from about 70,000 to 20,000 years ago, after which Acatenango's still-active northern Pico Central was constructed. The frequently active Fuego volcano grew during the Holocene.

Photo by Lee Siebert, 1988 (Smithsonian Institution).
Morning sun lights the upper SE flanks of the twin volcanoes of Fuego (left) and Acatenango (right), whose summits lie only 3 km apart along a N-S line. The modern Fuego volcano was constructed within a scarp left by collapse of the ancestral Mesata volcano, whose slopes appear to the right of the summit towards the saddle with Acatenango. In contrast to the dominantly andesitic Acatenango volcano, Fuego's activity has become more mafic with time, and historical eruptions have produced basaltic lava flows and tephras.

Photo by Lee Siebert, 1988 (Smithsonian Institution).
An incandescent column rises high above the summit of Fuego volcano and produces glowing avalanches down its flanks during an eruption on August 12-13, 1966. Ash clouds fill much of the sky in this view, probably of the east side of the volcano. The ash column rose to 12 km during this large, but unusually brief Fuego eruption.

Copyrighted photo by Dick Stoiber, 1966 (Dartmouth College).
Following mild eruptions that began on February 7, 1966, powerful vertical explosions in April produce a vigorous ash column that towers above the summit (not visible in this view). Major eruptions April 20 to May 1 were accompanied by pyroclastic flows and lava flows.

Photo by Bill Rose, 1966 (Michigan Technological University).
Scientists use a COSPEC (Correlation Spectraphotometer) instrument to measure the sulfur dioxide (SO2) content of a volcanic plume from Fuego volcano in Guatemala. Measurements of the concentrations of SO2 and other gases in volcanic plumes are useful tools for eruption monitoring. This photo was taken from Finca Capetillo NE of Fuego during its October 1974 eruption.

Copyrighted photo by Dick Stoiber, 1974 (Dartmouth College).
An ash plume rises from the summit crater of Fuego volcano in this closeup aerial view in March 1978. Intermittent minor explosive eruptions took place at Fuego from September 11, 1977, to August 8, 1979. The explosions were sometimes accompanied by pyroclastic flows and lava flows and originated from multiple vents in the summit crater.

Copyrighted photo by Dick Stoiber, 1978 (Dartmouth College).
A powerful eruption column towers above the summit of Fuego in October 1974 as pyroclastic flows sweep down the eastern (left-hand) flanks. This was the largest Fuego eruption since 1932 and produced pyroclastic flows that traveled up to 7 km down the east, SE, SW, and west flanks. Prevailing winds distributed ashfall primarily to the SW, in the opposite direction from this view.

Photo by William Buell, 1974.
Residents of Antigua Guatemala, the former colonial capital city, have observed violent outbursts from Volcán de Fuego for several centuries. A powerful vertical eruption column towers above the city in this October 1974 view of one of Fuego's largest historical eruptions. Pyroclastic flows can be seen descending the east (left-hand) flank. Topography has shielded Antigua from most of Fuego's onslaughts, diverting pyroclastic flows and mudflows down drainages to the east and south.

Photo by Paul Newton, 1974.
A powerful eruption column towers above the summit of Fuego in October 1974 as pyroclastic flows sweep down the SE (left-hand skyline) and NE flanks (center). Incandescent ejecta can be seen at the base of the eruption column, which reached to stratospheric levels. Prevailing winds distributed ashfall primarily to the SW. More than 0.2 cu km of ash was ejected during four distinct explosive pulses of 4 to 17 hours duration between October 14 and 23.

Photo by William Buell, 1974.
Pyroclastic flows sweep down the east flank of Fuego volcano, Guatemala, in October 1974, during one of the largest historical eruptions of the volcano. Ash clouds rise off the base of the pyroclastic flows, which traveled up to 7 km from the summit at estimated average velocities of 60 km/hr. The travel direction of pyroclastic flows is influenced by topography. The denser basal portion of the pyroclastic flows follows topographic lows on the flanks of the volcano--note a smaller pyroclastic flow descending a gully at the right.

Photo by William Buell, 1974.
Ash clouds roiling above a pyroclastic flow sweeping down the eastern flank of Fuego in October 1974 dramatically fill the entire field of view. The direction of movement of the rapidly moving pyroclastic flow was from right to left. Pyroclastic flows of comparable magnitude also traveled down the west and SW flanks of the volcano.

Photo by William Buell, 1974.
A small ash plume rising above the summit of Fuego volcano on October 10, 1977 is viewed here from the NE along the road to Alotenango, about 10 km away. Intermittent minor ash eruptions took place from September 11, 1977 to August 8, 1979, sometimes accompanied by pyroclastic flows and lava flows. Eruptions were often closely spaced. Note the two light-colored clouds left of the summit on this otherwise clear day. These are dispersed remnants of previous discrete eruption plumes.

Photo by Paulino Alquijay, 1977 (courtesy of Pete Newton).
A pyroclastic flow descending the east flank of Fuego volcano on January 8, 1979, is viewed from the city of Antigua Guatemala NE of the volcano. Intermittent explosive eruptions had been occurring since September 1977 and lasted until August 8, 1979.

Photo by Paulino Alquijay, 1979 (courtesy of Pete Newton).
Fuego (left) and Acatenango are two of several paired volcanoes in Guatemala. Southward-younging volcanism constructed these two large stratovolcanoes and flank vents perpendicular to the trend of the Guatemalan volcanic front. The chemistry of lavas also varied progressively from dominantly andesitic at Acatenango to increasingly basaltic at Fuego. Activity from the Pleistocene-Holocene Acatenango has continued only sporadically into historical time, but Fuego is one of the most active volcanoes in Guatemala, with about 60 historical eruptions.

Photo by Lee Siebert, 1988 (Smithsonian Institution).
The unvegetated summit of Fuego volcano (center) was constructed within and largely buries a massive collapse scarp in the older Meseta volcano, remnants of which form the flat ridge to the right of Fuego. This collapse, which may taken place about 8500 years ago, places a limit on the age of Fuego volcano, one of the youngest in Guatemala. The forested lower slopes of Acatenango volcano can be seen at the right in this view from the NE.

Photo by Lee Siebert, 1988 (Smithsonian Institution).
Three conical stratovolcanoes tower more than 3500 m above the Pacific coastal plain of Guatemala. Acatenango volcano, the highest of the three, rises to 3976 m altitude and is Guatemala's third highest peak, exceeded only by Tacaná and Tajumulco. A small steam plume pours from the summit of Fuego, Acatenango's twin volcano and one of Guatemala's most active. Volcán de Agua ("Water Volcano") at the extreme right rises above a low saddle between it and Volcán de Fuego ("Fire Volcano").

Photo by Lee Siebert, 1988 (Smithsonian Institution).
This roadcut provides a spectacular section through a debris-avalanche deposit hummock of the Fuego-Acatenango complex in Guatemala. The pronounced color mottling is a common texture of debris-avalanche deposits and distinguishes them from deposits produced by other volcanic processes such as mudflows or pyroclastic flows. This texture results from the transport of coherent segments of the volcano over long distances with only partial disaggregation. Individual lava flow segments and pyroclastic units can be traced across small offsetting faults.

Photo by Lee Siebert, 1988 (Smithsonian Institution).
The hummocky surface in the foreground in front of the twin volcanoes of Fuego and Acatenango in Guatemala is a massive Escuintla debris-avalanche deposit produced by collapse of the volcanic complex sometime during the late-Pleistocene to early Holocene. The avalanche, the largest known in Guatemala, has an estimated volume of about 15 cu km and traveled about 50 km. The avalanche traveled for its last 30 km over flat Pacific coastal plain slopes of less than 1 degree, illustrating the extremely high mobility of volcanic debris avalanches.

Photo by Jim Vallance, 1989 (Michigan Technological University).
The beautifully symmetrical Agua volcano towers to 3760 m above the near-sea-level Pacific coastal plain to its south. Activity at Agua has continued into the Holocene, but no historical eruptions are known. The foreground surface is part of a massive Escuintla debris-avalanche deposit most likely produced by collapse of the Acatenango-Fuego massif, out of view to the left.

Photo by Jim Vallance, 1989 (Michigan Technological University).
Agua volcano, seen here from the NE, is the most prominent volcano visible from Guatemala City. No historical eruptions have occurred at Agua volcano, despite its symmetrical, uneroded profile, and the volcano has not been studied in detail. Fuego volcano at the left center has been much more active, with about 60 eruptions during historical time.

Photo by Mike Carr, 1967 (Rutgers University).
A powerful vertical eruption column, lit by the rising sun, towers above the summit of Guatemala's Fuego volcano in October 1974. This dramatic view from Antigua Guatemala to the NE shows major pyroclastic flows sweeping down the east flank of Fuego. Pyroclastic flows traveled 7 km, but caused no fatalities. The 1974 eruption, the largest at Fuego since 1932, began with mild eruptions and small ash flows on October 10. The eruption intensified on October 14, with major vulcanian eruptions occurring that day, October 17-18, 19-20, and 23.

Photo by William Buell, 1974.
The twin volcanoes of Fuego (left) and Acatenango are seen here from the SSE. The two volcanoes consist of four major vents that were constructed along a 5-km-long N-S line, with the focus of volcanic activity progressively shifting to the south. The modern Fuego volcano is constructed within the scarp left by the collapse of an older volcano, Mesata, located between it and Acatenango.

Copyrighted photo by Stephen O'Meara, 1994.
The twin cones of 3763-m-high Fuego and 3976-m-high Acatenango, seen here from the SE, were constructed along a N-S line. The focus of volcanic activity at these paired volcanoes has migrated to the south. Construction of Acatenango volcano was completed prior to the formation of Fuego volcano, although their activity has in part overlapped. The prominent gully on the righthand side of Fuego is the rim of a scarp produced by the collapse of Meseta volcano, which preceded the growth of the modern cone of Fuego.

Copyrighted photo by Stephen O'Meara, 1994.
Intermittent explosive eruptions took place from Fuego volcano during a two-year-long period beginning in September 1977. Here an ash plume can be seen rising above the summit of Fuego on February 11, 1978. This view is from the WSW, with Acatenango volcano to the left and conical Agua volcano in the right background. The height of the eruption plume can be compared to the roughly 700 m vertical distance between the summit of Acatenango and the saddle between it and Fuego.

Photo by Ray Chuan, 1978 (courtesy of Bill Rose, Michigan Technological University).
A time exposure taken in 1978 from the NE shows the traces of star movement and an incandescent lava fountain at the summit of Fuego volcano. Intermittent minor ash eruptions took place from September 11, 1977 to August 8, 1979, sometimes accompanied by pyroclastic flows and lava flows.

Photo by Bill Rose, 1978 (Michigan Technological University).
A time exposure at night shows incandescent ejecta at the summit of Fuego volcano in 1962. Explosive activity and lava effusion took place August 4-20, 1962. The August eruptions also produced pyroclastic flows. Eruptive activity resumed in October prior to a large explosive eruption on November 9 that produced a 12-km-high eruption column. During the November eruption much of the NE-breached crater was filled by ejecta.

Photo by Alfredo MacKenney, 1962 (courtesy of Bill Rose, Michigan Technological University).
Frequent explosive eruptions have kept the summit of Fuego volcano unvegetated. Historical lava flows that originated from the summit crater descended through forests down the Río Taniluya (left center) and the Río Ceniza ("Sand River," on the right) on the SW flank of the volcano. Eruptions at Fuego have become more mafic with time. In contrast to the andesitic and basaltic-andesite products of the earlier Meseta edifice, Fuego's historical eruptions have produced basalts. Fuego's higher twin volcano Acatenango is at the upper left.

Photo by Bill Rose, 1980 (Michigan Technological University).
The barren slopes of Fuego volcano are seen here in an aerial view from the SE with its twin volcano, Acatenango, at the upper right. As with other Guatemalan paired volcanoes, activity began at the northern center, farthest away from the Central American trench (100 km to the south), and subsequently migrated to the south. Fuego, at the southern end, is one of the country's youngest and most active volcanoes.

Photo by Bill Rose, 1978 (Michigan Technological University).
Two vents in the summit crater of Fuego volcano were active simultaneously at the time of this February 24, 1978 aerial photograph. An small ash plume rises above the vent at the far side of the crater, while the spatter vent in the foreground ejects glowing lava fragments. This vent feeds a steaming and faintly incandescent lava flow that can be seen at the lower right. Intermittent moderate eruptions took place at Fuego over a two-year-long period from 1977 to 1979.

Photo by Bill Rose, 1978 (Michigan Technological University).
A closeup aerial view of the summit crater of Fuego in 1990 shows the products of both effusive and explosive eruptions. The crater walls truncate light-colored lava flows and lava agglutinate as well as dark-colored basaltic scoria deposits. Historical eruptions at Fuego have been exclusively basaltic in composition, continuing a trend towards more mafic volcanism in the Acatenango-Fuego volcanic pair. The slopes of Acatenango rise at the left in this view from the SW.

Photo by Bill Rose, 1990 (Michigan Technological University).
Dark ash-laden plumes rise simultaneously from two small cones in the summit crater of Fuego volcano on February 27, 1978. This aerial view is from the NE with the Pacific coastal plain in the background. Intermittent minor ash eruptions took place from September 11, 1977 to August 8, 1979. Strombolian eruptions from vents in the crater formed small pyroclastic cones and produced incandescent fountains at night.

Photo by Bill Rose, 1978 (Michigan Technological University).
Prevailing winds distribute an ash column from Fuego volcano to the SW in December 1978 as a small pyroclastic flow descends the SE (left) flank. Intermittent minor ash eruptions took place over a two-year interval from September 11, 1977 to August 8, 1979. Strombolian eruptions were sometimes accompanied by small pyroclastic flows and lava flows.

Photo by Bill Rose, 1978 (Michigan Technological University).
A small ash plume from the summit of Fuego volcano on February 27, 1978 is deflected to the south as a second plume rises from another vent immediately to the left. Symmetrical Agua volcano, inactive during historical time, towers in the distance. Fuego erupted intermittently from September 1977 to August 1979.

Photo by Bill Rose, 1978 (Michigan Technological University).
Small hills of the Escuintla debris avalanche, most likely from the Fuego-Acatenango massif, dot the Pacific coastal plain of Guatemala about 30 km from their source. This massive volcanic landslide is the largest known in Guatemala. The avalanche traveled about 50 km from the Fuego-Acantenango massif and covered about 420 sq km, with an estimated volume of about 15 cu km.

Photo by Bill Rose, 1988 (Michigan Technological University).
Acatenango (right) forms a twin volcano with Fuego (center). This view from the NE shows the twin summits of Volcán Acatenango, which was constructed during three eruptive periods post-dating the roughly 84,000-year-old Los Chocoyos Ash from Atitlán caldera. Construction of Yepocapa, the northern summit of Acatenango, was completed about 20,000 years ago. Growth of the southern and highest cone, Pico Central (also known as Pico Mayor), began at that time.

Photo by Bill Rose, 1986 (Michigan Technological University).
In contrast to their northern flanks, which rise above higher dissected topography of the Guatemalan highlands, the southern flanks of Fuego and Acatenango volcanoes tower more than 3500 m above farmlands of the Pacific coastal plain. Edifice failure of these volcanoes has occurred in the unbuttressed direction of the coastal plain, producing major debris avalanches that swept as far as 50 km from the volcanoes.

Photo by Bill Rose, 1970 (Michigan Technological University).
A small lahar travels down the Barranca Honda valley on the eastern side of Fuego volcano during the February-March 1973 eruption. The still-steaming channel of Barranca Honda was also affected by pyroclastic flows during the relatively moderate 1972 eruption.

Photo by Bill Rose, 1973 (Michigan Technological University).
Still-steaming pyroclastic-flow deposits from the 1974 eruptions fill barrancas on the eastern flanks of Fuego volcano. The deposit filling Quebrada El Pajal (right) was the NE-most produced during the 1974 eruption. Large andesitic blocks in the foreground were deposited near the terminus of the flow. The light-colored deposit extending from the summit in the center of the photo displays a prominent central channel confined within levees and flanked by overbank material.

Photo by Greg Hahn, 1974 (courtesy of Bill Rose, Michigan Technological University).
Following strong steam emissions on February 22, 1973, light ash eruptions beginning the next day were accompanied by pyroclastic flows down the Barranca Honda on the east flank of Fuego. Explosive eruptions continued until March 3, and resumed March 13 and 22-23. Less ash was erupted in 1973 than during the previous eruption in 1971, but pyroclastic flows were more voluminous and traveled farther downslope. This photo was taken from Finca Capetillo, near Alotenango.

Photo by Sam Bonis, 1973 (courtesy of Bill Rose, Michigan Technological University).
A pyroclastic flow descends drainages on the east flank of Fuego volcano in October 1975 as a vertical eruption column (upper right) towers above the summit. Intermittent minor ash eruptions took place May 28, July 23 to August 4, and September 19 to October 21, 1975. On October 11-12 and 16, ash fell in and west of Antigua. This photo was taken from Finca Capetillo, near Alotenango. Pyroclastic flows frequently travel down these same drainages, and had occurred during the two previous eruptions in 1973 and 1974.

Photo by Bill Rose, 1975 (Michigan Technological University).
Winds deflect a small February 27, 1978 ash plume from the summit crater of Fuego to the west. In the background is Fuego's twin volcano, Acatenango, which rises about 700 m above the saddle between it and Fuego. Intermittent minor ash eruptions took place from September 11, 1977 to August 8, 1979, sometimes accompanied by pyroclastic flows and lava flows.

Photo by Bill Rose, 1978 (Michigan Technological University).
Pyroclastic flows occurred frequently during the October 1974 eruption, and residents of nearby fincas are seen here carrying goods across a field almost oblivious to the dramatic pyroclastic flow descending the volcano's eastern flank behind them. Despite the frequency and magnitude of the pyroclastic flows, they affected relatively sparsely populated flanks of the volcano, and produced no fatalities.

Photo by William Buell, 1974.
Pyroclastic flows sweep down the Barranca Honda and an adjacent drainage on the east flank of Fuego volcano in February 1973. Following strong steam emissions on February 22, 1973, light ash eruptions beginning February 23 were accompanied by pyroclastic flows down the Barranca Honda on the east flank of Fuego. Explosive eruptions continued until March 3, and resumed March 13 and 22-23. This photo was taken from Finca Capetillo, near Alotenango.

Photo by Sam Bonis, 1973 (courtesy of Bill Rose, Michigan Technological University).
Of the four major Guatemalan volcanoes in this photo, only conical Agua volcano (right-center horizon) has not erupted during historical time. Lava flows from MacKenney cone (forming the slope in the left foreground) have filled in the moat of the caldera of Pacaya volcano almost to the level of the lower crater rim of Cerro Chino (right-center foreground), whose summit bristles with communication antennas. The twin volcanoes on the left horizon are Fuego (left), one of the most active in Guatemala, and Acatenango (right).

Photo by Lee Siebert, 1999 (Smithsonian Institution).
The flanks of Pacaya volcano provide a spectacular vista of the twin volcanoes of Fuego and Acatenango (left) and conical Agua volcano (right). Despite its youthful profile, Agua has not erupted in historical time. These impressive volcanoes all exceed 3500 m in elevation and rise from near sea level on the Pacific coastal plain to the south. Volcanism at the Acatenango-Fuego pair has migrated to the south, and Fuego, its summit kept free of vegetation by frequent eruptions, is one of Guatemala's most active volcanoes.

Photo by Lee Siebert, 1999 (Smithsonian Institution).
The historical city of Antigua Guatemala (top-right margin) is surrounded by three major stratovolcanoes in this Landsat view with north to the upper right. Dark-colored Acatenango volcano (upper left) and the unvegetated summit of Fuego volcano lie SW of the city, and Agua volcano (right-center) lies south. No historical eruptions from Agua are known, although mudflows in 1541 caused the abandonment of Ciudad Vieja, the previous capital city of Guatemala. Barrancas radiating SE from Fuego are light-colored from deposits of historical eruptions.

NASA Landsat image, 2000 (courtesy of Loren Siebert, University of Akron).
The distal end of the massive Escuintla debris-avalanche deposit is defined by the purple-colored area bounded on its SW side by the arcuate Río Naranjo at the bottom of the image. The avalanche traveled about 50 km from its source at Fuego-Acatenango complex (upper left), covering an exposed area of about 300 sq km on the Pacific coastal plain. Another debris avalanche from Pacaya volcano traveled about 25 km SW to the purplish area at the base of the Guatemalan Highlands. Guatemala City lies at the extreme upper right.

NASA Landsat image, 2000 (courtesy of Loren Siebert, University of Akron).
Guatemala's capital city (upper right) is flanked by four major stratovolcanoes and a large caldera. Steaming Pacaya volcano (lower right) was constructed near the southern rim of the partially lake-filled Amatitlán caldera, whose major late-Pleistocene silicic eruptions have produced thick pyroclastic-flow deposits exposed around Guatemala City. Conical Agua volcano (center) is a prominent landmark from the city, and the paired volcanoes of Acatenango and Fuego (left) lie to the west.

NASA Landsat image, 2000 (courtesy of Loren Siebert, University of Akron).
Ash eruptions from Fuego began on January 4, 2002 and continued intermittently into 2003. This January 8, 2002 image taken from the east shows an eruption plume and a ground-hugging smaller cloud just west from the summit area that may have been associated with reported pyroclastic flows. Effusion of lava flows down the east flank began in late January 2002. On August 2, 2002 explosive activity changed from strombolian to vulcanian.

Photo by Sid Halsor, 2002 (Wilkes University).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Carr M J, 1984. Symmetrical and segmented variation of physical and geochemical characterisitics of the Central American volcanic front. J Volc Geotherm Res, 20: 231-252.

Chesner C A, Halsor S, 1997. Geochemical trends of sequential lava flows from Meseta Volcano, Guatemala. J Volc Geotherm Res, 78: 221-237.

Chesner C A, Halsor S P, 2006. The Escuintla and La Democracia debris avalanche deposits, Guatemala: constraining their sources. In: Rose W I, Bluth G J S, Carr M J, Ewert J W, Patino L C, Vallance J W (eds), Volcanic hazards in Central America, {Geol Soc Amer Spec Pap}, 412: 105-120.

Chesner C A, Rose W I, 1984. Geochemistry and evolution of the Fuego volcanic complex, Guatemala. J Volc Geotherm Res, 21: 25-44.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Lyons J J, Waite G P, Rose W I, Chigna G, 2010. Patterns in open vent, strombolian behavior at Fuego volcano, Guatemala, 2005-2007. Bull Volc, 72: 1-15.

Martin D P, Rose W I, 1981. Behavioral patterns of Fuego volcano, Guatemala. J Volc Geotherm Res, 10: 67-81.

Mooser F, Meyer-Abich H, McBirney A R, 1958. Central America. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 6: 1-146.

Rodriquez L A, Watson M W, Rose W I, Branan Y K, Bluth G J S, Chigna G, Matias O, Escobar D, Carn S A, Fischer T P, 2004. SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 1999-2002. J Volc Geotherm Res, 138: 325-344.

Rose W I, Self S, Murrow P J, Bonadonna C, Durant A J, Ernst G G J, 2008. Nature and significance of small volume fall deposits at composite volcanoes: insights from the October 14, 1974 Fuego eruption, Guatemala. Bull Volc, 70: 1043-1067.

Sapper K, 1925. The Volcanoes of Central America. Halle: Verlag Max Niemeyer, 144 p.

Siebert L, Alvarado G E, Vallance J W, van Wyk de Vries B, 2006. Large-volume volcanic edifice failures in Central America and associated hazards. In: Rose W I, Bluth G J S, Carr M J, Ewert J W, Patino L C, Vallance J W (eds), Volcanic hazards in Central America, {Geol Soc Amer Spec Pap}, 412: 1-26.

Vallance J W, Schilling S P, Matias O, Rose W I, Howell M M, 2001. Volcano hazards at Fuego and Agua, Guatemala. U S Geol Surv Open-File Rpt, 01-431: 1-23.

Vallance J W, Siebert L, Rose W I, Giron J R, Banks N G, 1995. Edifice collapse and related hazards in Guatemala. J Volc Geotherm Res, 66: 337-355.

Yuan A, McNutt S R, Harlow D H, 1984. Seismicity and eruptive activity at Fuego Volcano, Guatemala; February 1975 - January 1977. J Volc Geotherm Res, 21: 277-296.

Volcano Types

Stratovolcano
Stratovolcano(twin)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Basalt / Picro-Basalt
Andesite / Basaltic Andesite
Minor
Trachyandesite / Basaltic trachy-andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
1,373
54,332
1,016,339
7,677,809

Affiliated Databases

Large Eruptions of Fuego Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.