Guagua Pichincha

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  • Ecuador
  • Ecuador
  • Stratovolcano
  • 2002 CE
  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 0.171°S
  • 78.598°W

  • 4784 m
    15692 ft

  • 352020
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

18 February-24 February 2009

The IG reported four moderate phreatic explosions from Guagua Pichincha were detected by the seismic network during 16-17 February, following a few days of slightly increased seismicity and rainfall. IG recommended that visitors stay out of the caldera.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)



 Available Weekly Reports


2009: February
2008: January
2006: February
2004: January | February
2003: April
2002: October | December
2001: January | February | March | May | November
2000: November | December


18 February-24 February 2009

The IG reported four moderate phreatic explosions from Guagua Pichincha were detected by the seismic network during 16-17 February, following a few days of slightly increased seismicity and rainfall. IG recommended that visitors stay out of the caldera.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


30 January-5 February 2008

IG reported seven moderate phreatic explosions from Guagua Pichincha on 1 February, following a few weeks of slightly increased internal activity and a few days of almost constant precipitation. IG recommended that visitors stay away from inside the caldera.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


15 February-21 February 2006

IG reported that seismic activity at Guagua Pichincha during 6-12 February decreased in comparison to the previous week, confirming that a small increase in activity around 5 February was related to brief phreatic activity. No explosions occurred during the report period and low-level volcanic tremor was recorded.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


8 February-14 February 2006

On 5 February, beginning around 1300, three small gas emissions occurred at Guagua Pichincha. IG reported that this phreatic activity was associated with accumulated rainfall that was heated by magmatic material from the previous eruptive period, and was not related to renewed volcanic activity. After the emissions, a series of seismic signals associated with rockfalls and long-period earthquakes were recorded. The signals were related to degassing that commonly occurs after emissions. Cloudy conditions prevented observations of the volcano. IG recommended that people should not visit Guagua Pichincha's crater since emissions or explosions can occur at any time.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


25 February-2 March 2004

Activity at Guagua Pichincha remained at low levels during 16-22 February, with only gas plumes rising from fumaroles. There was a slight increase in volcano-tectonic earthquakes. During 18-20 February, harmonic tremor was recorded.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


14 January-20 January 2004

During the afternoon of 7 January, strong rains occurred at Guagua Pichincha and a series of seismic signals attributed to rockfalls and lahars were recorded. A visit to the area by IG scientists on 13 January confirmed that a lahar traveled down the NNE wall of the volcano's crater. In addition, there were small fractures in the SE sector of the volcano and in the crater. IG noted that this activity does not indicate a change in volcanic activity at Guagua Pichincha.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


30 April-6 May 2003

This week Guagua Pichincha was marked by low-to-modest seismicity, which included earthquakes on 30 April and 1 May with magnitudes less than 3. Both had epicenters within an earthquake swarm N of Quito. Episodes of harmonic tremor appeared, most noteworthy on 4 and 5 May with each episode lasting under 40 minutes. Cloud cover obscured the crater area for much of the week (during 30 April and on 2 and 4 May), and civil defense observers monitoring the volcano noted little in the way of sulfurous odors and no noise. Improved visibility on 3 May enabled these observers to see modest fumaroles, with condensate visible at 3 to 100 m heights. This week's observations were similar to those of January, February, and March 2003.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


23 April-29 April 2003

During the week Guagua Pichincha continued to display seismic unrest, typically with several earthquakes per day but including 16 long-period earthquakes on 26 April. During 23, 24, 26, and 27 April observers on the mountain typically smelled sulfur, but qualitative assessments of fumarolic output varied. In conditions of poor visibility, observers sometimes heard the sound of gases escaping in the crater. In overview, the volcano's activity has not entirely tapered off.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


16 April-22 April 2003

The IG indicated that they detected seismic signals from a very minor Guagua Pichincha eruption on 17 April. The volcanologist on duty saw no visual signs of ash, implying that the seismic signals resulted from a very weak eruption with products confined to the summit crater. The IG also noted seeing similar seismic signals sporadically over the previous few days. The signals were thought to result from out-gassing, a class of behavior that if more energetic could generate larger ash clouds of impact to local residents and aviators. The IG also reported several volcano-tectonic earthquakes, seismic signals of rockfalls, and one long-period earthquake.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


4 December-10 December 2002

Based on information from IG, the Washington VAAC reported that an eruption occurred at Guagua Pichincha on 7 December at 2120. The height of the ash cloud produced from the eruption was not reported, and no ash was visible on satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)


30 October-5 November 2002

Based on information from IG, the Washington VAAC reported that explosions occurred at Guagua Pichincha on 3 November at 2056 and 2115. They could not determine the heights of the plumes produced from the explosions, or if they contained ash, because ash was already in the atmosphere from a large eruption that day at Reventador, ~100 km E of Guagua Pichincha.

Source: Washington Volcanic Ash Advisory Center (VAAC)


23 October-29 October 2002

A small increase in the number of phreatic explosions occurred at Guagua Pichincha following the 11 October explosion. The activity increase may have occurred due to heavy rain at the volcano.

Source: El Universo


16 October-22 October 2002

According to a news article, an explosion occurred at Guagua Pichincha on 11 October following 6 months with no explosions. Since the 11th, long-period and volcano-tectonic earthquakes, and continuous background tremor were recorded until at least the 17th.

Source: El Universo


28 November-4 December 2001

Tremor was recorded at Guagua Pichincha for ~16 hours after a phreatic eruption on 26 November. Signals from a relatively high number of rockfalls were recorded on seismographs, which is normal after an explosion. Two new craters formed during the explosion N of the 1981 crater. The following day, dark steam was observed rising 5 m above the craters. Volcanic and seismic activity remained at low levels after the 27th, with only low-level fumarolic activity occurring.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


21 November-27 November 2001

IG's seismic data showed that an approximately 20-minute-long phreatic explosion began at Guagua Pichincha on 26 November around noon. Cloudy conditions prohibited visual observations, but a cloud composed mainly of gas, with small amounts of ash, may have been produced. The volcanic cloud was not visible in satellite imagery; it is believed to have stayed around summit level. Continuous tremor was recorded through at least the rest of the day. The last explosion at Guagua Pichincha occurred on 25 May 2001.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


23 May-29 May 2001

Based on information from the IG, the Washington VAAC reported that on 25 May at 1110 a steam-and-ash emission from Guagua Pichincha's summit rose up to ~8.5 km a.s.l. The cloud was not visible on satellite imagery.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


28 March-3 April 2001

Based on information from the IG, the Washington VAAC reported that an ash cloud was observed at 0137 on 31 March. No ash was visible on GOES-8 imagery. The volcano remained at Alert Level Yellow.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


21 March-27 March 2001

The IG reported that during the week of 18-24 March a total of 806 long-period earthquakes were registered. However, 460 of those occurred on the 18th along with a moderate ash emission. Long-period event counts were below 20/day as of 21 March. Visual observations made by the Guards of the Refuge revealed that fumarolic activity increased, with higher steam columns on 18, 22, and 23 March, and a stronger sulfur smell until 22 March. No rockfall sounds were heard. The small number of rockfall signals detected as of 26 March suggests that lava dome 9 is stable. The volcano remained at Alert Level Yellow.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


14 March-20 March 2001

Based on information from the IG, the Washington VAAC reported that a moderate ash emission at 2145 on 18 March produced an ash cloud that rose to a height of ~5.8 km a.s.l. The ash cloud was not visible on GOES-8 imagery. According to the IG, during the week a large number of earthquakes, especially long-period events, were registered. The detection of a small number of rockfalls confirmed that lava dome 9 continued to slowly grow. The volcano remained at Alert Level Yellow.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


14 February-20 February 2001

On 13 February the Civil Defense reported that a crack formed in dome 9 and a small rock collapse occurred on the W side of the dome. On 14 February a rock collapse occurred on the S side of the dome. During a flight over the volcano on 15 February, IG personnel confirmed that dome 9 had grown during the week. The volcano remained at Alert Level Yellow.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


7 February-13 February 2001

Lava dome growth continued at dome 9 at a rate similar to that of previous weeks. Rockfalls were observed travelling to the SW towards Cristal River. The volcano remained at Alert Level Yellow.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


31 January-6 February 2001

The IG reported on 31 January that seismicity and volcanic activity remained at moderate levels. Continuous dome growth persisted at dome 9 and small morphologic changes were observed at the dome the previous week.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


17 January-23 January 2001

The IG reported that a small increase in seismic activity occurred and dome 9 continued gradual growth.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


10 January-16 January 2001

Guagua Pichincha has been producing fewer seismic events (~100/day) with the continuing growth of dome #9. During the week of 7-13 January the LP events were of greater magnitude and depth, registering on stations 10 km from the crater. Diego Viracucha of the Instituto Geofisica reported via radio on the morning of 14 January that a new crater appeared to be forming in dome #9. Diego informed two assistants that he was going to move several hundred meters W of seismic station "Pino" to take photos. While attempting that work he apparently slipped and fell 200 m into the caldera. He probably died immediately from head wounds and internal injuries. The site of the accident was 2.5 hours from GGP Refuge and it took all day to recover the body; because of the climatic conditions a helicopter could not be used. Recovery of the body was accomplished by six volcanologists from the IG, the Civil Defense, the Guards of the Refuge, the Red Cross, an elite group of police, various mountaineering groups, and family members. A cousin, Galo Viracucha, was injured during the recovery effort and later died as a result.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


27 December-2 January 2001

The IG reported that in comparison to November the number of long-period earthquakes, which has been shown at Guagua Pichincha to reflect the amount of lava dome growth, and the number of rockfalls decreased in December. Activity has remained relatively constant, with a daily average of 514 earthquakes.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


13 December-19 December 2000

The Guayaquil MWO reported to the Washington VAAC that an eruption occurred at 0148 on 15 December. No ash plume was visible in GOES-8 imagery and no further eruption details were reported. The IG reported that the high number of earthquakes that occurred during the week indicated that dome 9 continued to slowly grow.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


6 December-12 December 2000

Based on seismic measurements, the IG reported that an eruption may have occurred at 0030 on 8 December. Throughout the day seismic activity continued at a decreased rate and no ash was observed. The fact that the Washington VAAC did not detect ash in GOES-8 imagery during cloudless conditions supported the theory that an ash-producing eruption did not occur. The IG stated that the high number of earthquakes indicated that lava dome 9 continued to slowly grow.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


22 November-28 November 2000

Volcanic activity at Guagua Pichincha was low during the week and seismicity was relatively stable. There was a slight increase in seismicity on 27 November, but there were no indications of dramatic changes in volcanic activity.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


15 November-21 November 2000

Volcanic activity at Guagua Pichincha was low during the week and seismicity was relatively stable. No dramatic changes in the morphology of the lava dome were observed, but the IG suspects that slow and continuous dome growth may be occurring.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


8 November-14 November 2000

Volcanic activity at Guagua Pichincha was low during the week and seismicity was relatively stable. No dramatic changes in the morphology of the lava dome were observed.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)


1 November-7 November 2000

During the week moderate explosive activity produced small ash clouds at Guagua Pichincha. The Washington VAAC reported that one such cloud was visible on GOES-8 imagery at 0956 on 1 November and the IG reported that the ash cloud was near the summit level (~5 km a.s.l.). The IG also reported that seismicity continued after the eruption, suggesting that further explosive activity was possible. Small explosions and seismic activity suggested that dome growth occurred. The volcano is at Alert Level Yellow.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)


Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 2009 Feb 16 ] [ 2009 Feb 17 ] Uncertain 1  
[ 2008 Feb 1 ] [ 2008 Feb 1 ] Uncertain 1  
[ 2003 Apr 17 (in or before) ] [ 2003 Apr 17 ] Uncertain 1  
2002 Oct 11 2002 Dec 7 Confirmed 1 Historical Observations
2002 Apr 2002 Apr Confirmed 1 Historical Observations
2001 Nov 26 2001 Nov 26 Confirmed 1 Historical Observations North of 1981 crater
1998 Aug 7 2001 May 25 Confirmed 3 Historical Observations West and SE of 1981 crater
1997 Mar 1997 Oct 18 Confirmed 1 Historical Observations 1981 crater
1993 Mar 9 1993 Mar 12 Confirmed 1 Historical Observations 1981 crater
1990 Apr 16 1990 May 10 Confirmed 1 Historical Observations 1981 crater
1985 May 1985 Jun Confirmed 1 Historical Observations 1981 crater
1981 Aug 31 ± 5 days 1982 Nov (?) Confirmed 1 Historical Observations NE side of 1660 lava dome
1881 Mar 10 Unknown Confirmed 2 Historical Observations
1869 Jul 22 1869 Aug 24 Confirmed 2 Historical Observations
1869 Mar Unknown Confirmed 2 Historical Observations
1868 Aug Unknown Confirmed 2 Historical Observations
1868 Mar 19 1868 Mar 22 Confirmed 2 Historical Observations
1831 Unknown Confirmed 3 Historical Observations
1830 Unknown Confirmed 2 Historical Observations
1660 Oct 27 1660 Nov 28 Confirmed 4 Historical Observations
1582 Jun 5 1598 Confirmed 3 Historical Observations
[ 1580 ] [ Unknown ] Uncertain 2  
[ 1577 ] [ Unknown ] Uncertain 2  
1575 Sep 8 Unknown Confirmed 2 Historical Observations
1566 Oct 17 1566 Nov 16 Confirmed 3 Historical Observations
[ 1560 ] [ Unknown ] Uncertain 2  
[ 1539 ] [ Unknown ] Uncertain 2  
[ 1538 ] [ Unknown ] Uncertain 3  
[ 1535 ] [ Unknown ] Uncertain 2  
[ 1534 ] [ Unknown ] Uncertain 2  
[ 1533 ] [ Unknown ] Uncertain 2  
0930 ± 100 years Unknown Confirmed 5 Radiocarbon (corrected)
0550 ± 75 years Unknown Confirmed   Radiocarbon (corrected)
0070 ± 75 years Unknown Confirmed 4 Radiocarbon (corrected)
1230 BCE ± 75 years Unknown Confirmed   Radiocarbon (corrected)
1860 BCE ± 100 years Unknown Confirmed   Radiocarbon (corrected)
2090 BCE ± 75 years Unknown Confirmed   Radiocarbon (corrected)
3500 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
4850 BCE ± 1000 years Unknown Confirmed   Tephrochronology
6200 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
6300 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
6400 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
6650 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
7000 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

Barberi F, Ghigliotti M, Macedonio G, Orellana H, Pareschi M T, Rosi M, 1992. Volcanic hazard assessment of Guagua Pichincha (Ecuador) based on past behavior and numerical models. J Volc Geotherm Res, 49: 53-68.

Garcia-Aristizabal A, Kumagai H, Samaniego P, Mothes P, Yepes H, Monzier M, 2007. Seismic, petrologic, and geodectic analysis of the 1999 dome-forming eruption of Guagua Pichincha volcano, Ecuador. J Volc Geotherm Res, 161: 333-351.

Hall M L, 1977. El Volcanismo en El Ecuador. Quito: Biblioteca Ecuador, 120 p.

Hantke G, Parodi I, 1966. Colombia, Ecuador and Peru. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 19: 1-73.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Johnson J B, Aster R C, Ruiz M C, Malone S D, McChesney P J, Lees J M, Kyle P R, 2003. Interpretation and utility of infrasonic records from erupting volcanoes. J Volc Geotherm Res, 121: 15-63.

Robin C, Samaniego P, Le Pennec J-L, Fornari M, Mothes P, van der Plicht J, 2010. New radiometric and petrological constraints on the evolution of the Pichincha volcanic complex (Ecuador). Bull Volc, 72: 1109-1129.

Robin C, Samaniego P, Le Pennec J-L, Mothes P, van der Plicht J, 2008. Late Holocene phases of dome growth and plinian activity at Guagua Pichincha volcano (Ecuador). J Volc Geotherm Res, 176: 7-15.

Samaniego P, Robin C, Monzier M, Mothes P, Beate B, Garcia A, 2006. Guagua Pichincha volcano: Holocene and late Pleistocene activity. Cities on Volcanoes 4, Quito, Ecuador, 23-27 Jan, 2006, Field trip A4: 1-15.

Guagua Pichincha and the older Pleistocene Rucu Pichincha stratovolcanoes form a broad volcanic massif that rises immediately to the west of Ecuador's capital city, Quito. A lava dome is located at the head of a 6-km-wide breached caldera that formed during a late-Pleistocene slope failure of Guagua Pichincha about 50,000 years ago. Subsequent late-Pleistocene and Holocene eruptions from the central vent in the breached caldera consisted of explosive activity with pyroclastic flows accompanied by periodic growth and destruction of the central lava dome. Many minor eruptions have occurred since the beginning of the Spanish era at Guagua Pichincha, which is one of Ecuador's most active volcanoes. The largest historical eruption took place in 1660, when ash fell over a 1000 km radius, accumulating to 30 cm depth in Quito. Pyroclastic flows and surges also occurred, primarily to the west, and affected agricultural activity, causing great economic losses.