Cleveland

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  • United States
  • Alaska
  • Stratovolcano
  • 2014 CE
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  • Last Known Eruption
  • 52.825°N
  • 169.944°W

  • 1730 m
    5674 ft

  • 311240
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Most Recent Weekly Report: 25 June-1 July 2014


AVO reported earlier in June that an explosion from Cleveland on the evening of 5 June was detected on the Dillingham acoutstic infrasound array and at seismic stations at Korovin volcano. The brief event was similar to previous explosions at Cleveland, and generated a small detached plume with a weak ash signal observed in satellite imagery. The cloud was at an altitude of about 7.6 km (25,000 ft) a.s.l., had moved about 140 km SW, and rapidly dissipated. The last previous explosion at was 6 March, seen by residents of Nikolski who reported small ash puffs.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


Most Recent Bulletin Report: October 2013 (BGVN 38:10)


Dome growth and destruction during 2012-2013

In the previous Bulletin report (BGVN 37:01) we discussed a cycle of lava-dome growth within the summit crater from late 2011 through early 2012. That cycle of extrusion and destruction of domes continued into 2013. The lava dome observed on 30 January 2013 persisted to the end of this reporting period, September 2013. The dynamic conditions at Cleveland caused the Alaska Volcano Observatory (AVO) to report numerous changes in the Aviation Color Code and Alert Level, fluctuating between Yellow/Advisory and Orange/Watch throughout this time period (table 5).

Table 5.During 2012-2013, AVO announced changes in the Aviation Color Code and Volcano Alert Level for Cleveland. AVO and other US Observatories use a combination color code and alert level system that addresses both airborne and ground-based hazards (Gardner and Guffanti, 2006); the lowest level in this 4-step system is Normal/Green and the highest is Warning/Red. Courtesy of USGS-AVO.

Aviation Color Code/ Volcano Alert Level Date of Change
Orange/Watch 31 Jan. 2012
Yellow/Advisory 23 Mar. 2012
Orange/Watch 28 Mar. 2012
Yellow/Advisory 30 May 2012
Orange/Watch 19 Jun. 2012
Yellow/Advisory 5 Sept. 2012
Orange/Watch 10 Nov. 2012
Yellow/Advisory 21 Nov. 2012
Orange/Watch 6 Feb. 2013
Yellow/Advisory 8 Mar. 2013
Orange/Watch 4 May 2013
Yellow/Advisory 4 Jun. 2013

Continued explosions during 2012-2013. Cleveland has a history of frequent, minor ash emissions particularly during 2005-2009 (McGimsey and others, 2007; Neal and others, 2011) and with more frequency during 2011-2013 (Guffanti and Miller, 2013; De Angelis and others, 2012). During 2012-2013, Cleveland remained unmonitored by ground-based seismic instrumentation; volcanic unrest was primarily detected by the seismic network located on nearby Umnak Island (figure 12). Observations were also conducted with satellites that have capabilities of distinguishing ash from meteorological clouds during clear conditions: GOES (Geostationary Operational Environmental Satellite), POES (Polar Operational Environmental Satellite which carries the AVHRR scanner), and the Terra and Aqua satellites that carry MODIS sensors.

Figure 12. Locations of Cleveland volcano (red triangle) and the infrasound stations in Alaska. Black dots are individual infrasound sensors co-located with seismic monitoring stations, yellow dots are infrasound arrays. The inset shows Umnak Island where the Okmok volcano stations are located; this is the closest seismic network to Cleveland. Map modified from De Angelis and others, 2012.

Additional assessments of explosive activity in this period were aided by (1) direct observations from mariners or pilots (PIREPS); (2) near real-time recordings of ground-coupled airwaves that characteristically arrive at seismic stations as extremely slow velocity signals, ~1 order of magnitude smaller than typical seismic velocity in the crust (De Angelis and others, 2012); (3) new infrasound detection capabilities recently expanded to include a station on Akutan (~500 km ENE of Cleveland).

De Angelis and others (2012) determined that 20 explosions were detected between December 2011 and August 2012, particularly by infrasound sensors as far away as 1,827 km from the active vent, as well as ground-coupled acoustic waves recorded at seismic stations across the Aleutian Arc. By retrospectively examining the record of airwaves from Cleveland, those authors determined that many explosions had gone unnoticed in satellite images, likely because of poor weather conditions that obscured the signal or because these explosions were brief, small, and lofted little ash.

Significant ash explosions in April-June 2012 and May 2013. During the 2012-2013reporting period , explosions from Cleveland's summit crater were most frequently detected during April and June 2012 (figure 13). Additional explosions were reported by AVO through July 2013. Relative quiescence (which included minor thermal anomalies visible in satellite images) followed and continued through September 2013.

Figure 13. Satellite image of Cleveland collected on 9 June 2012 by the satellite Worldview-2. Snow persisted on the flanks during this time, but recent, minor ash deposits were visible around the summit crater. In this view, N is at the top of the image and the narrow isthmus connecting Cleveland to the rest of Chuginadak Island is at the R-hand side of the image (although not visible here). Courtesy of USGS-AVO and Digital Globe.

During 2012-2013, at least two explosions were large enough to generate ash plumes that reached >4 km above the summit crater. Both were reported by the Anchorage Volcanic Ash Advisory Center (VAAC) on 7 April 2012 and 4 May 2013. The April event produced a plume that rose ~6 km a.s.l.; AVO reported that ash drifted E at 18 m/s. The 4 May 2013 event (figure 14) generated an ash plume that rose ~4.6 km a.s.l. Based on POES data and AVO observations, the ash drifted SE at ~10 m/s and dissipated within 5 hours.

Figure 14. (A) AVHRR satellite image of Cleveland was taken at 0643 on 4 May 2013. This infrared image shows elevated temperatures that were present at Cleveland's summit and a small, low-level eruption plume containing minor amounts of ash trailed to the E. The thermal anomaly appears as a white dot in the center of the image. Courtesy of USGS-AVO/UAF-GI. (B) True-color Terra MODIS satellite image acquired at 2050 on 4 May 2013 shows an eruption plume from Cleveland. The diffuse ash plume extended from Cleveland's summit and across the SW point of Umnak Island. Courtesy of USGS-AVO and Land Atmosphere Near-real time Capability for EOS (LANCE) system operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS).

During 2012-2013, AVO reported that explosions were frequently attributed to dome destruction. Those events often completely removed the new lava domes from the crater (table 6).

Table 6.Cleveland's lava dome history during 2012-2013 based on a variety of observations of the Cleveland summit crater. Note that an earlier dome was destroyed during 25-29 December 2011 and was confirmed absent by 24 January 2012. Courtesy of USGS-AVO.

New Dome Date Observations
30 January 2012  •40 m across
 •Dome was gone by 11 March 2012
26 March 2012 •70 m across
 •Dome was gone by 4 April 2012
25 April 2012 •25 m across
 •Dome was gone some time before 29 April 2012
3 May 2012 •25 m wide
 •Dome was gone by 6 May 2012
30 January 2013 •100 m wide
•Dome persisted through September 2013

More on elevated surface temperatures during 2012-2013. In addition to the case shown in figure 14A, thermal anomalies in the vicinity of Cleveland's summit crater were frequently detected during this reporting period. AVO inferred that these observations reflected a variety of volcanic activity such as fresh, hot tephra from recent explosions, the hot open conduit at the bottom of the summit crater, incandescent rock such as the above mentioned domes (table 6) at the surface, or hot volcaniclastic flow deposits on the flanks (figure 15).

Figure 15. Composite image of the Cleveland summit area compiled from Landsat-8 images acquired on 8 June 2013. N is at the top of the image. Thermal infrared data are overlain onto a visible wavelength image; the extent of lava flows erupted during early May 2013 appears bright with colors corresponding to temperatures in the key (upper-L-hand corner). Temperature values are given in Kelvin, and range from 303-312 K (86-102 °F). The longest lava flows extended to ~715 m downslope from the summit. The summit was also covered by dark ash deposits and is surrounded by a low cloud deck. Courtesy of USGS-AVO.

AVO reported that a satellite-based thermal alarm was triggered on 12 June 2012, attributed to the formation of hot lahars or rubble flows on Cleveland's flanks. While no lava dome was present at that time (see table 6), this was a significant event that transported debris to 700 m a.s.l. on the NW flank (note that Cleveland has a summit elevation of 1,730 m). Other deposits, likely from other lahars, were mobilized on the NNW and NNE flanks. The deposits were mainly confined to drainages; deposits extended >1.5 km in length. Flowage features on the SE and SW flanks reached >1 km in length. AVO scientists also noted that all flanks had shown signs of melted snow but cautioned that the visual effect could also be attributed to non-eruptive remobilization of existing fragmental material on the steep flanks.

Volcaniclastic deposits were also noted based in satellite images on 10 November 2012. These features were located on the E flank and extended ~1 km down the slope.

References: De Angelis, S., Fee, D., Haney, M., and Schneider, D., 2012. Detecting hidden volcanic explosions from Mt. Cleveland Volcano, Alaska with infrasound and ground-coupled airwaves, Geophysical Research Letters, 39, L21312, doi:10.1029/2012GL053635.

Gardner, C.A. and Guffanti, M.C., 2006. U.S. Geological Survey's Alert Notification System for Volcanic Activity, USGS Fact Sheet 2006-3139.

Guffanti, M., and Miller, T., 2013. A volcanic activity alert-level system for aviation: review of its development and application in Alaska: Natural Hazards, 15 p., doi:0.1007/s11069-013-0761-4.

McGimsey, R.G., Neal, C.A., Dixon, J.P., and Ushakov, Sergey, 2007. 2005 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2007-5269, 94 p., available at http://pubs.usgs.gov/sir/2007/5269/.

Neal, C.A., McGimsey, R.G., Dixon, J.P., Cameron, C.E., Nuzhaev, A.A., and Chibisova, Marina, 2011. 2008 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2010-5243, 94 p., available at http://pubs.usgs.gov/sir/2010/5243.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA (URL: http://www.gi.alaska.edu/ ), and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.dggs.alaska.gov/); and Anchorage Volcanic Ash Advisory Center (VAAC), 6930 Sand Lake Road, Anchorage, AK 99502, USA (URL: http://vaac.arh.noaa.gov/list_vaas.php).

Index of Weekly Reports


2014: January | February | June
2013: February | March | May
2012: January | February | March | April | May | June | July | August | September | November
2011: March | July | August | September | October | November | December
2010: May | June | August | September
2009: April | June | September | October | December
2008: February | May | July | August | December
2007: July | August | September
2006: February | May | September | October
2005: June | July | August | October | November
2001: February | March | April | May

Weekly Reports


25 June-1 July 2014

AVO reported earlier in June that an explosion from Cleveland on the evening of 5 June was detected on the Dillingham acoutstic infrasound array and at seismic stations at Korovin volcano. The brief event was similar to previous explosions at Cleveland, and generated a small detached plume with a weak ash signal observed in satellite imagery. The cloud was at an altitude of about 7.6 km (25,000 ft) a.s.l., had moved about 140 km SW, and rapidly dissipated. The last previous explosion at was 6 March, seen by residents of Nikolski who reported small ash puffs.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


19 February-25 February 2014

AVO reported that small explosions from Cleveland were detected by infrasound and lightning alarms at 1917 on 24 February and 0135 on 25 February. Small ash clouds from the explosions were detected in satellite images several hours after the events drifting at an altitude of about 5 km (16,000 ft) a.s.l. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 January-14 January 2014

AVO reported that no further activity at Cleveland had been detected after three brief explosions on 28 and 30 December, and 2 January; satellite images suggested no new lava effusion. On 10 January AVO lowered the Volcanic Alert Level to Advisory and the Aviation Color Code to Yellow.

Source: US Geological Survey Cascades Volcano Observatory (CVO)


1 January-7 January 2014

AVO reported that at 1229 on 28 December 2013 an explosion at Cleveland was detected on distant seismic and infrasound instruments. Although satellite images did not detect ash it was possible the explosion generated minor ash emissions. Elevated surface temperatures following the explosion were detected. Another similar explosion was detected at 1906 on 30 December, and a third brief explosion was detected at 1900 on 1 January 2014. Following the second and third explosions, satellite images detected distinct ash plumes, detached from the summit, drifting 75-100 km N at unknown altitudes. On 2 January AVO raised the Volcanic Alert Level to Watch and the Aviation Color Code to Orange. No further activity was detected during 3-7 January.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 May-4 June 2013

On 4 June AVO reported that no explosions from Cleveland had been detected since 6 May, and there was no evidence of lava effusion since 13 May. Weakly elevated surface temperatures detected in recent clear-weather satellite images were consistent with cooling of a newly emplaced lava flow. AVO lowered the Volcanic Alert Level to Advisory and the Aviation Color Code to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 May-28 May 2013

AVO reported that during 22-23 May elevated surface temperatures over Cleveland were observed in satellite images. Clouds obscured views during 24-26 May. Slightly elevated surface temperatures, consistent with a cooling lava flow, were observed in several satellite images during 26-28 May. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 May-21 May 2013

AVO reported that during 14-15 and 18-19 May elevated surface temperatures over Cleveland were observed in satellite images. Clouds obscured views during 16 and 20-21 May. Satellite image analysis revealed that a small lava flow had breached the SE rim of the summit crater and traveled as far as1.5 km down the flank. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 May-14 May 2013

AVO reported that during 8-9 May no further explosions had been detected at Cleveland based on regional infrasonic data. Cloud cover prevented satellite observations of the crater. Clear satellite views revealed vigorous steam plumes during 10-11 May and thermal anomalies during 10-14 May. On 14 May AVO noted that analysis of recent satellite imagery revealed a 100-m-wide lava flow, breaching the SE rim of the summit crater, and extending about 1.5 km down the SE flank. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 May-7 May 2013

AVO reported that on 4 May the infrasound network detected three short-duration explosions from Cleveland at 0500, 0717, and 1144. A small, low-altitude ash cloud along with high surface temperatures at the summit were observed in satellite images starting at 0717. In a report posted at 1822 AVO noted that both webcam and satellite images suggested continuous low-level emissions of gas, steam, and minor amounts of ash over the past several hours with a faint plume drifting E below 4.6 km (15,000 ft) a.s.l. The Volcanic Alert Level was raised to Watch and the Aviation Color Code was raised to Orange.

On 5 May the amplitude of the Cleveland infrasonic tremor, as measured by the ground-coupled airwaves on the Okmok seismic network, 120 km NE, decreased from its peak activity the evening before. Satellite images again detected continuous low-level emissions of gas, steam, and minor amounts of ash producing a faint plume that drifted E below 4.6 km (15,000 ft) a.s.l. Explosions were detected at 1123 on 5 May and 0800 on 6 May. A thermal anomaly continued to be detected. A news article stated that some airplanes were diverted away from Cleveland.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 March-12 March 2013

AVO reported that during 6-7 March clouds obscured satellite views of Cleveland's lava dome. On 8 March AVO noted that the lava dome had remained unchanged since 6 February, and the last thermal anomalies were observed on 26 February. Although cloud cover often prevents observations of the dome, clear views between 1 and 5 March verified no changes. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 February-5 March 2013

AVO reported that during 27 February-5 March clouds obscured satellite views of Cleveland's lava dome. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 February-26 February 2013

AVO reported that during 20-26 February clouds obscured satellite views of Cleveland's lava dome. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 February-19 February 2013

AVO reported that during 12-15 February elevated surface temperatures from Cleveland's lava dome were detected in satellite images. Clouds obscured views of the dome during 16-19 February. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 February-12 February 2013

On 6 February AVO reported that satellite imagery acquired on 30 January indicated that a lava dome had grown in Cleveland's summit crater, prompting AVO to raise the Volcanic Alert Level to Watch and the Aviation Color Code to Orange. The dome was about 100 m in diameter and may have begun forming as early as 24 January when elevated surface temperatures were observed in satellite images. The size and shape of the dome appeared to be unchanged based on satellite data acquired on 2 February. Elevated surface temperatures from the lava dome were detected during 5-6 and 8-11 February.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 November-27 November 2012

On 21 November AVO noted that no explosions at Cleveland had been detected since 10 November, nor evidence of renewed lava-dome growth. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow. Elevated surface temperatures were detected in satellite imagery during 21-24 November. Clouds obscured satellite and web camera views during 25-27 November.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


14 November-20 November 2012

AVO reported that no new activity was observed in cloudy- to- mostly-cloudy satellite images and web-camera views during 14-15 November. Clouds completely obstructed views during 16-18 November. The Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


7 November-13 November 2012

AVO reported that on 6 November thermal infrared satellite images of Cleveland showed elevated surface temperatures. Clouds obscure views of the lava dome during 7-9 November. A small ash cloud drifting ENE was detected in satellite imagery at 1147 on 10 November. The Volcano Alert Level was raised to Watch and the Aviation Color Code was raised to Orange. At 1843 the ash cloud was observed almost 100 km S of Dutch Harbor (260 km ENE). No new activity was observed in mostly cloudy images during11-13 November. Post-event analysis of infrasound data suggested that a small explosion likely occurred at 1125 on 10 November.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


5 September-11 September 2012

On 5 September, AVO reported that satellite views of Cleveland showed no evidence of further eruptive activity since the last explosion on 20 August. Fresh lava within the summit crater was last detected in images in early May. The Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 August-4 September 2012

AVO reported that satellite images of Cleveland from 17 August showed that the summit crater was tephra-covered, funnel-shaped, and contained no lava dome. Cloud cover prevented observations during 28 August-3 September. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 August-28 August 2012

AVO reported that nothing unusual was observed at Cleveland in cloudy to partly cloudy satellite images during 22-26 August. Slightly elevated surface temperatures were detected at the summit during 23-24 August. Cloud cover prevented observations during 27-28 August. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 August-21 August 2012

AVO reported that nothing unusual was observed at Cleveland in cloudy to partly cloudy satellite images during 15-16, 18, and 20-21 August. A small explosion was detected on 17 August by seismic and infrasound instruments on neighboring volcanoes. No evidence of an ash cloud was visible in satellite images following the event. Another small explosion on 19 August produced a low-level ash cloud, observed in satellite imagery, that drifted SE. Retrospective analysis of ground-coupled airwaves in seismic data further confirmed the explosion. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 August-14 August 2012

AVO reported that during 8-11 August elevated surface temperatures from Cleveland were detected in partly-cloudy satellite images. Cloud cover prevented observations on 12 August. Nothing unusual was observed in images during 13-14 August. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 August-7 August 2012

AVO reported that cloud cover prevented satellite and web-camera observations of Cleveland during 1-3 and 5-6 August. A small explosion at 0838 on 4 August was detected based on retrospective analysis of infrasound data. Satellite images showed a brief, faint steam plume about four hours after the event and also detected elevated surface temperatures in several clear views of the volcano. On 7 August elevated surface temperatures were detected in partly-cloudy satellite images. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 July-31 July 2012

AVO reported that cloud cover mostly prevented satellite and web camera observations of Cleveland during 25-31 July. Slightly elevated surface temperatures were detected in satellite images during 25-26 and 29-30 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


18 July-24 July 2012

AVO reported that elevated surface temperatures from Cleveland were detected in satellite images during 18-20 July. Images revealed nothing unusual during 20-22 July. Cloud cover mostly prevented observations during 22-24 July; a steam plume rose from the crater on 23 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


11 July-17 July 2012

AVO reported that on 11 July a low-altitude ash cloud from Cleveland was detected in satellite imagery. During 12-15 July cloud cover prevented views of the volcano. Elevated surface temperatures were detected in images on 15 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 July-10 July 2012

AVO reported that cloudy conditions at Cleveland often prevented observations during 4-9 July. Clear views of the volcano by the web camera on the morning of 6 July revealed a distinct plume, likely containing water vapor and volcanic gas, drifting several tens of miles downwind from the summit. Elevated surface temperatures were detected in satellite images on 10 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 June-3 July 2012

AVO reported that cloudy conditions at Cleveland mostly prevented observations during 26-28 June. An area of possibly elevated surface temperatures was observed in images during 27-28 June. Cloud cover prevented observations during 29 June-3 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 June-26 June 2012

AVO reported that a small amount of ash from an explosion at Cleveland on 19 June was visible in satellite imagery drifting ESE. During 20-24 June thermal anomalies were detected in satellite imagery. On 21 June a small steam-and-gas plume was visible in web camera images. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 June-19 June 2012

AVO reported that during 12-19 June meteorological cloud cover often prevented satellite views of Cleveland. Elevated surface temperatures at the summit were detected using infrared imagery during 12-13 and 18-19 June. A pilot report, a web camera image, and infrasound data all indicated that an ash-producing explosion occurred around 1405 on 19 June. The pilot report suggested that the cloud altitude was 10 km (35,000 ft) a.s.l. and the infrasound data indicated that the eruption duration was short. The Volcano Alert Level was raised to Watch and the Aviation Color Code was raised to Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 June-12 June 2012

AVO reported that during 5-6 June elevated surface temperatures at Cleveland's summit were detected in satellite imagery. A low-level plume that rose to an altitude of 3.5 km (11,500 ft) a.s.l. was observed by a web camera on 6 June. A strong sulfur odor was reported by observers in Nikolski (75 km E). Clouds prevented views of the volcano on 7 June. Minor deposits of ash near the summit crater were observed in satellite images during 9-10 June and elevated surface temperatures were detected during 11-12 June. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


30 May-5 June 2012

On 30 May AVO reported that no explosions or renewed lava-dome growth had been detected at Cleveland since 9 May. The Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow. On 4 June a possible small explosion was detected by infrasound. No eruption plume was observed in cloudy satellite images, but elevated surface temperatures were detected at the summit.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


23 May-29 May 2012

AVO reported that during 23-29 May satellite observations of Cleveland's summit crater revealed nothing unusual; no ash emissions or other signs of unrest were detected or reported. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


16 May-22 May 2012

AVO reported that during 16-22 May satellite observations of Cleveland's summit crater revealed nothing unusual; no ash emissions or other signs of unrest were detected or reported. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


9 May-15 May 2012

AVO reported that during 9-12 and 15 May cloudy weather conditions prevented satellite observations of Cleveland's summit crater. Elevated surface temperatures were detected in images on 13 May and possibly the next day. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


2 May-8 May 2012

Based on analyses of satellite images, AVO reported on 4 May that the small lava dome recently emplaced in Cleveland's summit crater had been destroyed late in the previous week, but the explosion was too small to be detected by distant infrasound and seismic networks. A small new dome was extruded following the explosion and was the fifth dome to be observed in this eruptive episode which began in July 2011. During 4-5 May two small explosions were detected. No ash was observed with the mostly-cloudy conditions. Satellite observations were obscured by clouds during 6-8 May.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 April-1 May 2012

AVO reported that elevated surface temperatures were detected over Cleveland in satellite imagery during 25-29 April and possibly on 30 April. Observations showed that a small lava dome, 25 m across, had recently been emplaced.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


18 April-24 April 2012

AVO reported that elevated surface temperatures were observed over Cleveland in satellite imagery during 17-18 April. An explosion on 19 April at 0438, detected by seismometers at Makushin and Okmok volcanoes, generated an ash cloud the rose 4-6 km (13,100-19,700 ft) a.s.l. and drifted S. Satellite images showed block-and-ash deposits extending for up to 1 km down the S flank. A possible weak thermal anomaly was detected in images during 20-21 April.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


11 April-17 April 2012

AVO reported that elevated surface temperatures were observed over Cleveland in satellite imagery during 11-12 April. Two explosions were detected on 13 April by distant seismic stations and infrasound arrays. Neither of these explosions produced an ash cloud that could be detected in satellite images. There was no evidence of explosive activity or eruption of lava in the summit crater during 14-17 April. No seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 April-10 April 2012

AVO reported that a small explosion from Cleveland was detected at 0112 on 4 April by distant seismic stations and infrasound arrays. Weather conditions prevented the detection of a possible eruption cloud in satellite images or by visual observation of the summit. Observations the next day revealed a thermal anomaly and that the 70-m-diameter lava dome had been destroyed by the explosion. This was the third lava dome that was erupted and subsequently destroyed by explosive events since the eruption began in July 2011.

On 6 April two short-duration explosions occurred at about 1635 and 2126. The resulting eruption clouds were ash poor and did not rise above 3 km (10,000 ft) a.s.l. Elevated surface temperatures were observed using infrared satellite images near the times of the explosions. Satellite observations were obscured by clouds during 8-10 April. No seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


28 March-3 April 2012

AVO reported that on 28 March the Volcano Alert Level for Cleveland was raised to Watch and the Aviation Color Code was raised to Orange due to the formation of a new lava dome, observed in satellite imagery, which extruded in the summit crater during the previous week. During 29 March-3 April cloud cover prevented observations of the crater. Elevated surface temperatures consistent with a hot lava dome were detected in infrared satellite imagery on 4 April. No seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 March-27 March 2012

AVO reported on 23 March that the Volcano Alert Level and Aviation Color Code for Cleveland were lowered to Advisory and Yellow, respectively, because no explosions had been detected since 13 March and lava-dome growth was not evident after that.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


14 March-20 March 2012

AVO reported that a small explosion from Cleveland was detected at 1455 on 13 March by distant seismic stations and infrasound arrays. Weather conditions prevented the detection of a possible eruption cloud in satellite images or by visual observation of the summit. No other activity was detected during 14-19 March. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


7 March-13 March 2012

AVO reported that a small explosion from Cleveland was detected at 1905 on 7 March by distant seismic stations and infrasound arrays. Weather conditions prevented the detection of a possible eruption cloud in satellite images or by visual observation of the summit. Another small explosion was detected at 1605 on 9 March and again weather conditions prevented observations. No other activity was detected during 11-13 March. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 February-6 March 2012

AVO reported that during 24 February-2 March satellite images of Cleveland revealed no unusual activity and no significant changes in the size of the lava dome. A weak thermal anomaly was detected in satellite imagery on 3 March. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 February-28 February 2012

AVO reported that satellite observations of Cleveland during 22-28 February revealed that the growth of the lava dome continued at a slow rate. Cloud cover over the volcano prevented views of the lava dome during 22 and 25-28 February. On 23 February a thermal anomaly was detected in partly cloudy satellite images. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 February-21 February 2012

AVO reported that during 15-18 and 20-21 February no observations of elevated surface temperatures or ash emissions from Cleveland were noted. On 17 February, AVO reported that partly-cloudy satellite observations over the past week revealed that the lava dome had grown to about 60 m in diameter. On 19 February an elevated surface temperature was detected in satellite images. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 February-14 February 2012

AVO reported that during 8-14 February there were no observations of elevated surface temperatures or ash emissions from Cleveland because of partly cloudy conditions. On 10 February satellite observations revealed that the lava dome had grown to about 50 m in diameter. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 February-7 February 2012

AVO reported that during 2-7 February cloud cover over Cleveland prevented views of the lava dome in the summit crater. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 January-31 January 2012

AVO reported that on 31 January the Volcano Alert Level for Cleveland was raised to Watch and the Aviation Color Code was raised to Orange due to the formation of a new 40-m-wide lava dome in the summit crater that was observed in satellite imagery on 30 January. The lava dome that formed during the past fall and winter was removed by explosive activity on 25 and 29 December 2011. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


28 December-3 January 2012

AVO reported that an ash cloud from Cleveland rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted 80 km ESE on 29 December. AVO raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. During 30 December-3 January there were no new signs of explosive activity; the Volcano Alert Level was lowered to Advisory and the Aviation Color Code to Yellow on 30 December. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


2 November-8 November 2011

AVO reported that a thermal anomaly over the lava dome surface in Cleveland's summit crater was visible on 2 November, although cloudy views mostly prevented observations. On 3 November AVO lowered the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow because satellite observations indicated no significant change in the size of the lava dome, and no explosive activity or ash emissions had been reported. Cloud cover continued to prevent observations during 4-6 November. Satellite imagery showed slightly elevated temperatures near the volcano's summit during 6-7 November. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


26 October-1 November 2011

AVO reported that a radar image from 23 October indicated a lowering of the lava dome surface in Cleveland's summit crater. During 26 October-1 November cloud cover prevented views of the lava dome. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


19 October-25 October 2011

AVO reported that during 19-23 October cloud cover over Cleveland prevented views of the lava dome in the summit crater. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


12 October-18 October 2011

AVO reported that during 12-13 October cloud cover over Cleveland prevented views of the lava dome in the summit crater. Partly cloudy satellite views during 14-18 October showed elevated surface temperatures from the crater indicative of continued growth of the lava dome. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


5 October-11 October 2011

AVO reported that during 5-6 and 9-11 October cloud cover over Cleveland prevented views of the lava dome in the summit crater. Partly cloudy satellite views during 7-8 October showed elevated surface temperatures at the summit. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


28 September-4 October 2011

AVO reported that during 27-28 September and 30 September-1 October thermal anomalies over Cleveland's summit lava dome were detected in satellite images and suggested that the lava dome continued to slowly grow. Clouds obscured views on 29 September and during 2-3 October. Elevated surface temperatures were detected by satellite in partly cloudy images acquired during 3-4 October. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 September-27 September 2011

AVO reported that during 20-21 September no observations of elevated surface temperatures or ash emissions from Cleveland were visible in partly cloudy satellite images. Clouds obscured views on 22 September. Elevated surface temperatures were observed in satellite images during 23-24 September, suggesting that the lava dome eruption was continuing. On 25 September AVO noted that elevated surface temperatures were not observed in several clear views of the volcano by satellite during the previous 24-hour period. Cloud cover prevented observations on 26 September.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


14 September-20 September 2011

AVO reported that during 13-17 September no lava-dome activity in Cleveland's summit crater was observed in partly cloudy satellite images. During 17-18 September a thermal anomaly was detected in satellite images. A report on 20 September noted that recent observations revealed the lava dome had grown to about 165 m in diameter, remained contained within the crater, and was 20 m below the E crater rim.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


7 September-13 September 2011

AVO reported that although cloud cover often prevented observations of Cleveland during 7-12 September, a thermal anomaly on the lava dome was visible during 8-9 and 12 September. A possible anomaly was visible on 10 September. The anomalies suggested that lava-dome growth was continuing, although no activity was observed in partly cloudy satellite images during 12-13 September. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


31 August-6 September 2011

On 30 August, AVO reported that satellite observations during the previous two weeks indicated that lava-dome growth at Cleveland had paused. AVO lowered the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow. During 31 August-2 September cloud cover prevented views of the summit crater, but a thermal anomaly at the summit was observed during 3-5 September. Observations on 6 September indicated that the lava dome had resumed growth, reaching 120 m in diameter and filling the floor of the crater. AVO raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


17 August-23 August 2011

AVO reported that during 17-23 August cloud cover over Cleveland prevented observations of the summit crater. On 21 August AVO noted that a weak, 1-pixel thermal anomaly was observed in a recent satellite view during a cloud break. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


10 August-16 August 2011

On 9 August AVO reported that possible thermal anomalies on Cleveland were detected in satellite imagery. Cloud cover prevented observations of the summit area during 10-12 and 15-16 August, but several thermal anomalies were visible during 13-14 August. A scientist that flew 32 km N of the volcano on 14 August observed small white "puffs" of steam rising 30-60 m above the summit, even though most of the volcano was obscured by clouds. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


3 August-9 August 2011

AVO reported that observations from 2 August of the lava dome growing in Cleveland's summit crater revealed growth from about 40 m to 50 m in diameter since 29 July. Weak thermal anomalies were observed in satellite imagery during 2-3, 5, and 7-9 August when cloud cover was limited or absent. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 July-2 August 2011

AVO reported that on 2 August the Volcano Alert Level for Cleveland was raised to Watch and the Aviation Color Code was raised to Orange due to the formation of a 40-m-wide lava dome in the summit crater that was observed on 29 July. The lava dome was extruded sometime after 7 July following the last clear view of the summit area, however thermal anomalies observed since 19 July suggested that the dome had extruded since that time.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 July-26 July 2011

AVO reported that on 20 July the Volcano Alert Level for Cleveland was raised to Advisory, and the Aviation Color Code was raised to Yellow, due to thermal anomalies visible in satellite imagery during 19-20 and 22 July. Cloud cover prevented observations during 21 and 23-26 July. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


30 March-5 April 2011

On 31 March, AVO lowered the Volcano Alert Level and the Aviation Color Code for Cleveland to Unassigned noting that no eruptive activity had been confirmed during the previous few months. Neither significant thermal anomalies nor ash deposits on snow were observed in recent satellite imagery.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 September-28 September 2010

AVO reported that during 25-26 September a weak thermal anomaly from Cleveland was detected in satellite imagery. Cloud cover prevented views of the volcano during 22-24 and 27-28 September. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 September-21 September 2010

AVO reported that on 15 September a thermal anomaly from Cleveland was detected in satellite imagery. Cloud cover prevented views of the volcano during 16-21 September. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 September-14 September 2010

AVO reported that during 7-8 September clear-weather satellite views of Cleveland showed no thermal anomalies or recent deposits on the flanks. The Volcano Alert Level and the Aviation Color Code were lowered to Unassigned. On 11 September, a thermal anomaly was observed in satellite imagery. The next day a possible ash plume seen in satellite imagery rose to the estimated altitude of 7.6 km (25,000 ft) a.s.l. and drifted E. The Volcano Alert Level and the Aviation Color Code were again raised to Advisory and Yellow, respectively. A thermal anomaly was again visible during 13-14 September.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 September-7 September 2010

AVO reported that during 31 August-1 September thermal anomalies from Cleveland were detected in satellite imagery. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 August-31 August 2010

AVO reported that on 26 August the Volcano Alert Level for Cleveland was raised to Advisory, and the Aviation Color Code was raised to Yellow, due to a persistent thermal anomaly near the summit visible in satellite imagery on most days during 16-24 August. Cloudy weather conditions prevented views of the summit during 25-29 August. A thermal anomaly was again seen in satellite imagery at night during 29-30 August. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


9 June-15 June 2010

AVO reported that on 11 June the Volcano Alert Level and the Aviation Color Code for Cleveland was lowered to Unassigned; no activity or unrest was detected during 4-11 June.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


2 June-8 June 2010

AVO reported that a weak thermal anomaly from Cleveland was detected in satellite imagery on 2 June. Cloud cover mostly prevented observations during 3-8 June. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


26 May-1 June 2010

AVO reported a small ash emission from Cleveland on 30 May. A detached plume seen in satellite imagery rose no higher than 4.9 km (16,000 ft) a.s.l. and drifted SW. Satellite images the next day revealed minor (uncharacterized) flow deposits on the upper flanks. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


19 May-25 May 2010

On 25 May, AVO raised the Volcano Alert Level for Cleveland to Advisory and the Aviation Color Code to Yellow because thermal anomalies from the crater were seen in satellite imagery during the previous few days.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


16 December-22 December 2009

On 18 December, AVO reported that a diffuse ash plume emitted from Cleveland on 12 December was retrospectively detected in satellite imagery. No other activity was noted.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


14 October-20 October 2009

On 19 October, AVO reported that no eruptive activity from Cleveland had been observed since the brief eruption on 2 October. The Aviation Color Code and the Volcano Alert Level were lowered to Unassigned. Cleveland is not monitored by a real-time seismic network, thus the levels "Green" or "Normal" do not apply because background activity is not defined.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


30 September-6 October 2009

A small explosive eruption of Cleveland on 2 October prompted AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. A detached ash cloud at estimated altitudes of 4.6-6.1 km (15,000-20,000 ft) a.s.l. was seen on satellite imagery; the cloud drifted about 600 km NE and dispersed over the Bering Sea. No further activity was reported. On 5 October, the Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow. No seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


24 June-30 June 2009

A small explosive eruption of Cleveland on 25 June prompted AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. An ash cloud that detached from the volcano was seen on satellite imagery moving S at an estimated altitude of 4.6 km (15,000 ft) a.s.l. No further activity was reported. On 27 June, AVO lowered the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 April-5 May 2009

On 1 May, AVO decreased the Aviation Color Code and the Volcano Alert Level for Cleveland to "Unassigned" because no volcanic activity had been detected since late January. Cleveland is not monitored by a real-time seismic network, thus the levels "Green" or "Normal" do not apply because background activity is not defined.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


31 December-6 January 2009

AVO reported that cloud cover prevented satellite observations of Cleveland during 31 December, and 1, 3, and 5 January. The brief explosive emission of ash was detected on 2 January. A resultant ash plume rose to an altitude of 6 km (20,000 ft) a.s.l. and drifted about 240 km ESE. A thermal anomaly over the summit was detected on 4 January. No current seismic information was available because Cleveland does not have a real-time seismic network. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


24 December-30 December 2008

AVO reported that on 24 December the Volcano Alert Level for Cleveland was raised to Advisory, and the Aviation Color Code was raised to Yellow, due to a persistent thermal anomaly near the summit visible on satellite imagery acquired the day before. The previous Alert Levels were listed as Unassigned. Cloud cover prevented observations during 25-27 December. The thermal anomaly was again detected on 28 December, but was absent the next two days. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 August-26 August 2008

AVO reported that cloud cover prevented satellite observations of Cleveland during 20-26 August, although a possible thermal anomaly was present on 24 August. On 25 August the Volcano Alert Level was lowered to Advisory and the Aviation Color Code to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 August-19 August 2008

AVO reported that cloud cover prevented satellite observations of Cleveland during 13-18 August. The Volcano Alert Level remained at Watch and the Aviation Color Code at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 August-12 August 2008

On 6 August, AVO reported that the thermal anomalies noted at Cleveland's summit and on the W, S, and SE flanks had decreased in intensity since first noted on 21 July, indicating that the lava flows slowed or stopped. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code to Yellow. During 7-10 August, a weak thermal anomaly at the summit was intermittently visible when not obscured by clouds and drifting ash from the eruption of Kasatochi (about 400 km WSW). On 11 August, thermal anomalies on satellite imagery indicated that lava flowed down the flanks. The Volcano Alert Level was raised to Watch and the Aviation Color Code to Orange. On 12 August, an ash plume rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted 100 km SW.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


30 July-5 August 2008

AVO reported that thermal anomalies at Cleveland's summit, detected on satellite imagery during 30 July-5 August, suggested the presence of an active lava flow. A diffuse plume drifted less than 20 km NE, N, and NW at an altitude of 6.1 km (20,000 ft) a.s.l. on 31 July. On 5 August, thermal anomalies on the W, S, and SE flanks possibly indicated the presence of pyroclastic flows or hot lahars. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


23 July-29 July 2008

AVO reported that satellite views of Cleveland were hindered on 23 July due to cloud cover. On 24 July, a low-level ash plume and a strong thermal anomaly were noted near the summit. The thermal anomaly suggested the presence of an active lava flow. The thermal anomaly continued to be detected during 26-28 July and possible ash plumes drifted SE, E, and NE at altitudes of 3-6.1 km (10,000-20,000 ft) a.s.l. during 27-29 July.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


16 July-22 July 2008

On 21 July, AVO raised the Volcano Alert Level for Cleveland to Watch and the Aviation Color Code to Orange based on reports from pilots and observers on fishing boats. Reports from fishing boats indicated that an eruption started at about 1200 and ash near sea level may have drifted NW. Pilots reported that an ash-and-steam plume rose to altitudes of 4.6-5.2 km (15,000-17,000 ft) a.s.l. and drifted SE. Observations of satellite imagery on 22 July revealed a steam plume possibly containing some ash drifting more than 50 km ESE at altitudes of 3-6.1 km (10,000-20,000 ft) a.s.l. A strong thermal anomaly interpreted as a possible lava flow was also present in the imagery.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


7 May-13 May 2008

On 9 May, AVO reported that an increasing number of thermal anomalies at Cleveland were visible on satellite imagery during the previous two weeks. A small ash plume rose to an altitude of below 4.6 km (15,000 ft) a.s.l. on 7 May. A ship N of Nikolski (75 km ENE) reported a dusting of ash around the same time. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 February-4 March 2008

AVO reported that a weak thermal anomaly and an ash plume from Cleveland were visible on satellite imagery on 29 February. The ash plume rose to an altitude of below 3 km (10,000 ft) a.s.l. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 February-26 February 2008

AVO reported that a low-level ash plume from Cleveland was visible on satellite imagery and drifted about 300 km SE on 22 February. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 February-19 February 2008

AVO reported that a minor explosion from Cleveland on 15 February produced a small, diffuse ash plume that rose to an altitude of below 3 km (10,000 ft) a.s.l. and drifted NW. The Volcanic Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 February-12 February 2008

AVO reported that diffuse ash plume from Cleveland was observed on satellite imagery drifting 12 km SE at an altitude below 1.5 km (5,000 ft) a.s.l. during a break in cloud cover on 8 February. Later that day AVO received pilot reports of an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and observed the plume on satellite imagery drifting NW. Due to the increased activity, the Volcanic Alert Level was raised to Watch and the Aviation Color Code was raised to Orange. No precursory or current seismic information is available because Cleveland does not have a real-time seismic network. During 10-11 February, a thermal anomaly was possibly visible on satellite imagery. The Volcanic Alert Level was lowered back to Advisory and the Aviation Color Code was lowered to Yellow on 12 February.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


5 September-11 September 2007

AVO lowered the Volcanic Alert Level for Cleveland from Watch to Advisory and the Aviation Color Code from Orange to Yellow on 6 September. AVO noted that since late July, ash and gas plumes were absent in satellite imagery and no reports of activity were received. Clouds obscured satellite and web camera views during 5-11 September.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 August-4 September 2007

Clouds obscured satellite and web camera views of Cleveland volcano during 29 August-4 September. A clear view of the crater on 30 August and 1 September revealed thermal anomalies at the summit. No current seismic information is available because Cleveland does not have a real-time seismic network. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 August-28 August 2007

Clouds obscured satellite and web camera views of Cleveland volcano during 22-28 August. A clear view of the crater on 23 and 28 August revealed thermal anomalies at the summit. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 August-21 August 2007

Clouds obscured satellite and web camera views of Cleveland volcano during 15-20 August. A clear view of the crater on 20 August revealed a thermal anomaly at the summit. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 August-14 August 2007

Clouds obscured satellite and web camera views of Cleveland volcano during 8-13 August. A few clear views of the crater during 13-14 August revealed multiple thermal anomalies. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 August-7 August 2007

A thermal anomaly in the crater of Cleveland was intermittently visible on satellite imagery during 2-6 August, though bad weather often limited observations. Photographs from 27 July and a pilot report from 2 August indicated fresh volcanic ejecta on the slopes and summit. The E portion of Chuginadak Island was dusted with ash on 3 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 July-31 July 2007

A thermal anomaly in the crater of Cleveland was visible on satellite imagery during 25-26 July. The Volcanic Alert Level remained at Watch and the Aviation Color Code remained at Orange through at least 30 July. On the 27th AVO noted that low-level eruptive activity continued. Three small SO2 clouds produced by small explosions on 20 July were detected in OMI satellite data provided by the University of Maryland Baltimore County. No further explosive activity had been detected by the OMI sensor since that time. AVO is unable to track local earthquake activity related to volcanic unrest.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); OMI Sulfur Dioxide Group


18 July-24 July 2007

AVO raised the Volcanic Alert Level for Cleveland from Advisory to Watch and the Aviation Color Code from Yellow to Orange on 20 July. The change in Alert Level was based on the presence of an intense thermal anomaly in the crater and associated steam-and-gas plume observed on satellite imagery. The thermal anomaly continued to be detected on satellite imagery during 22-23 July.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 October-31 October 2006

AVO raised the Alert Level for Cleveland from Advisory to Watch on 28 October based on pilot reports of an ash plume. Satellite imagery confirmed the presence of a plume drifting ENE at an altitude estimated at 6.1 km (20,000 ft) a.s.l. A pilot reported that the altitude of the plume was in excess of 9.1 km (30,000 ft) a.s.l. On 30 October, the Alert Level was lowered back to Advisory because of no further evidence of activity.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 September-12 September 2006

On 7 September, AVO raised the level of Concern Color Code for Cleveland from unassigned to Yellow after a short-lived explosion on 24 August was verified by video footage. The resultant ash plume reached an altitude of about 3 km (~10,000 ft) a.s.l. and produced ash fall. An hour later, only minor steaming from the summit was noted. A weak thermal anomaly in the summit crater was present in subsequent satellite images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


24 May-30 May 2006

The ash plume from Cleveland observed from the International Space Station on 23 May, drifted SW and had mostly dissipated by 24 May. No further activity was recorded. On 26 May AVO downgraded the Concern Color Code from Yellow to "Not Assigned".

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Washington Volcanic Ash Advisory Center (VAAC)


17 May-23 May 2006

On 23 May, AVO reported that an astronaut aboard the International Space Station observed an ash plume from Cleveland at 1500. A plume was visible on satellite imagery at 1507 that drifted SW and reached a height of 6.1 km (20,000 ft) a.s.l. At 1700, an image showed the detached ash plume 130 km SW of Cleveland. The Concern Color Code was raised to Yellow. No precursory or current seismic information is available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


3 May-9 May 2006

On the morning of 2 May beginning at 0101, a thermal anomaly and continuous plume from Cleveland were seen on satellite imagery. The plume extended ~50 km SW of the volcano and was visible on satellite imagery for about 6 hours. Satellite data suggested a maximum cloud height of ~1 km (3,500 ft) a.s.l. There was no indication of ash in the observed cloud. No further activity was detected at Cleveland after 2 May. Cleveland was not assigned a Concern Color Code because there is no real-time seismic network at the volcano to monitor seismic changes.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 February-14 February 2006

AVO decreased the Concern Color Code at Cleveland from Orange to Yellow on 11 February. They received no information about further eruptive activity or ash emissions after 6 February, and no ash clouds were detected on satellite imagery. Clouds obscured the volcano during 6-11 February, therefore, AVO could not verify that eruptive activity ended and it is possible that the volcano remains in a state of low-level unrest.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Anchorage Volcanic Ash Advisory Center (VAAC)


1 February-7 February 2006

An ash cloud emitted from Cleveland was detected on satellite imagery beginning at 0757 on 6 February, leading AVO to increase the Concern Color Code to Red from an unassigned code (Cleveland does not normally have a Concern Color Code because it is not seismically monitored, therefore no definitive information about background activity is available). An image at 0900 on the same day showed a small ash cloud ~130 km ESE of the volcano. Initial data suggested that the cloud was at a height of ~6.7 km (22,000 ft) a.s.l. The ash cloud detached from the volcano and there was no indication of continuous ash emission. Ash had largely dissipated on satellite imagery by 1341. AVO received no information about additional ash emissions, so they decreased the Concern Color Code to Orange around 1655 on 6 February.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Anchorage Volcanic Ash Advisory Center (VAAC); Washington Volcanic Ash Advisory Center (VAAC)


23 November-29 November 2005

Activity at Cleveland further decreased during 18-25 November. Following a brief ash burst on 7 October, no further ash emissions were noted. AVO did not detect a temperature anomaly in the vicinity of the volcano after 6 November. Based on this information, AVO concluded that the likelihood of significant ash-producing events decreased, so they terminated Concern Color Code Yellow. Cleveland is not monitored with seismic equipment, therefore AVO did not assign Color Concern Code Green.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


12 October-18 October 2005

After a brief ash burst at Cleveland on 7 October, no further eruptive activity was recorded at the volcano. On 10 October, AVO reduced the Concern Color Code from Orange to Yellow. AVO warned that although there were no additional ash bursts noted, they consider the volcano restless. Explosive ash-producing events could occur at any time and without warning (owing to the lack of local seismic monitoring). AVO continued to monitor the volcano using satellite imagery.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


5 October-11 October 2005

AVO staff recorded a small ash cloud emitted from Cleveland on satellite imagery on the morning of 7 October. Based on satellite data, a small eruption occurred at Cleveland sometime before 0300. The ash cloud was located E of the volcano and ~150 km ESE of Dutch Harbor at 0900. AVO, in consultation with the National Weather Service, estimated that the top of the ash cloud reached no more than 4.6 km (15,000 ft) a.s.l. The ash cloud dissipated and was not detected on satellite imagery after 1000. The Concern Color Code at Cleveland was Orange on 7 October. During 7-10 October, there were no new observations of eruptive activity at Cleveland on satellite imagery, by pilots, or ground-based observers, so the Concern Color Code was reduced to Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


31 August-6 September 2005

A thermal feature at Cleveland was detected on several satellite images obtained on 31 August, but there was no evidence of eruptive activity at the volcano. Cleveland is not seismically monitored, so AVO did not assign it a Concern Color Code.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


24 August-30 August 2005

AVO reduced the Concern Color Code at Cleveland from Yellow to "Not Assigned" on 27 August because there had been no evidence of activity at the volcano since a thermal feature was observed on satellite imagery on 11 August. Cleveland does not have a real-time seismic network; volcanoes without seismic networks are not assigned a color code of Green because without the seismic data, AVO has no definitive information that the level of activity of the volcano is at background.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


3 August-9 August 2005

Satellite imagery of Cleveland volcano on 4 August showed a thermal anomaly, indicating that activity continued. Cleveland remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 July-2 August 2005

Satellite imagery of Cleveland during 22-29 July showed minor steaming from the volcano's summit, possible fresh localized ash deposits, and a weak thermal anomaly. According to AVO, these observations suggested that low-level volcanic unrest continued. Cleveland remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


20 July-26 July 2005

Satellite imagery taken on 18 July showed steam emanating from Cleveland's summit and evidence of minor ash emissions. Satellite imagery from the rest of 15-22 July was obscured by meteorological clouds. Cleveland remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


6 July-12 July 2005

Satellite imagery of Cleveland taken during 1-8 July revealed increased activity at the volcano, so AVO assigned a Concern Color Code of Yellow on 7 July. The images showed increased heat flow, thin ash deposits, and possible debris flows extending ~1 km down the volcano's flanks from the summit crater. AVO reported that based on historical eruptions at Cleveland, it is possible that explosive, ash-producing events could occur at any time without warning (due to a lack of seismic monitoring).

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 June-5 July 2005

Satellite imagery of Cleveland taken during 24 June to 1 July showed increased heat flow from the volcano and a possible debris flow. AVO stated that although observations were inhibited by cloudy weather, they indicated the possibility of increased volcanic activity. AVO did not assign a Concern Color Code to Cleveland due to the lack of seismic monitoring at the volcano and limited satellite observations. The last eruption at Cleveland began in February 2001 when three explosive events produced ash clouds as high as 12 km (39,400 ft) a.s.l.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


23 May-29 May 2001

Neither eruptive activity nor thermal anomalies have been observed at Cleveland during the previous 6 weeks.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


16 May-22 May 2001

Cleveland was observed on satellite images numerous times during the week and no thermal anomalies were detected. AVO had received no reports of significant volcanic activity from pilots, residents, or satellite remote-sensors since the last eruption on 19 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


9 May-15 May 2001

Cleveland was obscured by clouds during most of the week and no thermal anomalies were observed. AVO had received no reports of significant volcanic activity from pilots, residents, or satellite remote-sensors since the last eruption on 19 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


2 May-8 May 2001

Volcanic unrest continued at Cleveland through 4 May. The volcano was obscured by clouds during the report period and no thermal anomalies were observed. Pulses of volcanic tremor continued to be detected by an AVO seismic network 230 km to the E of the volcano. AVO personnel installed a temporary seismic-recording instrument at Nikolski, ~70 km to the E of the volcano, in an attempt to verify that the source of the tremor is Cleveland. AVO had received no reports of significant volcanic activity from either pilots, residents, or satellite remote-sensors since the last eruption on 19 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


25 April-1 May 2001

Volcanic unrest continued at Cleveland through 27 April. During this time a thermal anomaly was observed on satellite imagery when weather permitted. Low pulses of volcanic tremor continued to be detected by an AVO seismic network 230 km to the E of the volcano. AVO had received no reports of significant volcanic activity from either pilots, residents, or satellite remote-sensors since the last eruption on 19 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


18 April-24 April 2001

Volcanic unrest continued at Cleveland through 20 April. A thermal anomaly was persistently detected in satellite imagery on days when the weather was clear to partly cloudy. Low-level pulses of volcanic tremor were detected several times during the week by an AVO seismic network 230 km to the E of the volcano. AVO received no reports of significant volcanic activity from either pilots, residents, or satellite remote sensors.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


11 April-17 April 2001

Volcanic unrest continued at Cleveland through 13 April. A thermal anomaly was last detected on satellite imagery on 8 April, but cloudy conditions in the area may have hidden the anomaly from the satellite's view during the rest of the week. Low-level pulses of volcanic tremor were detected several times during the week by an AVO seismic network 230 km to the E of the volcano. AVO received no reports of significant volcanic activity from either pilots, residents, or satellite remote sensors.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 April-10 April 2001

The AVO reported that unrest continued at Cleveland. This was based on data from a seismic network 230 km E of the volcano that intermittently recorded low-level volcanic tremor over the last several weeks. Since the 19 March eruption there have been no reports of significant activity from either pilots, residents, or satellite remote sensors. The thermal anomaly previously observed in the vicinity of the volcano has been absent since 23 March. Based on current data and the volcano's historical activity, the AVO warned that additional ash-producing eruptions are possible at any time.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


28 March-3 April 2001

The AVO reported that after 24 March, satellite imagery has not shown the thermal anomaly that had been visible since the 19 March eruption of Cleveland. No further explosive activity has been reported. Occasional avalanching of material from the steep flanks of Cleveland may produce small, localized plumes.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 March-27 March 2001

On 20 March AVO could no longer detect the ash cloud resulting from the 19 March eruption of Cleveland. Based on satellite data, AVO estimates that the explosive eruption started at 1430 on 19 March and may have lasted as long as 6 hours. The National Weather Service estimated the top of the ash cloud was as high as 9.1 km a.s.l. No ashfall was reported in Nikolski, 75 km E of the volcano. A thermal anomaly detected in satellite imagery following the explosive activity was still visible as of 23 March. The elevated temperature indicated by the anomaly is most likely the result of continued unrest at the volcano and the cooling of recently erupted material.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Washington Volcanic Ash Advisory Center (VAAC)


14 March-20 March 2001

The AVO reported that at 1430 on 19 March an explosive eruption at Cleveland was detected on satellite imagery. The National Weather Service estimated the top of the cloud to be at ~ 9 km a.s.l. An observer in the town of Nikolski reported that at about 1900 a strong haze resulting from the eruption extended SE from the volcano, but there was no ashfall. The Washington VAAC concluded that the ash cloud had dissipated by 0230 on 20 March because it was no longer visible on satellite imagery.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Washington Volcanic Ash Advisory Center (VAAC)


7 March-13 March 2001

The AVO reported that an explosive eruption at Cleveland began at 0500 on 11 March. The resultant ash cloud was visible on satellite imagery from the onset of the eruption and after it ended 3 hours later. Wind-data analysis suggested that the ash cloud reached a height of 6-7.6 km a.s.l. By 1400 the main part of the ash cloud was detached from the volcano and drifting to the E. Satellite imagery from 2030 showed that the ash cloud was located in two main regions; one region was centered ~80 km S of Dutch Harbor and was ~80 km in diameter, and the other was centered ~160 km SE of Dutch Harbor and extended ~160 km E to W and ~65 km N to S. Both areas of ash were visible on satellite imagery through 1315 on 12 March. In addition, a thermal anomaly on the volcano, which was first detected shortly after the eruption began, persisted. AVO interpreted the thermal anomaly to indicate that unrest was continuing at Cleveland and that further explosive activity could occur at anytime. By 0930 on 13 March the ash cloud was no longer visible on satellite imagery.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Anchorage Volcanic Ash Advisory Center (VAAC); Tokyo Volcanic Ash Advisory Center (VAAC)


28 February-6 March 2001

The AVO reported that no further eruptive activity was observed or detected at Cleveland since the 19 February eruption. During 19 February to 2 March, GOES-10 imagery showed a weak thermal anomaly that was probably related to hot material deposited on the flanks of the volcano on the 19th. Photographs taken a few days after the eruption showed significant accumulation of spatter and lava blocks high on the steep flanks of the volcano; occasional avalanching of this debris may produce small, localized ash plumes.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 February-27 February 2001

The ash cloud produced from the 19 February eruption of Cleveland volcano was visible on GOES-10 imagery through 1700 on 21 February. The AVO reported that a thermal anomaly was detected on satellite imagery during 21-26 February. On 22 February a pilot reported that steam was observed rising from near the SE shoreline of the volcano where an apparently fresh deposit entered the sea. The deposit may have been an active lava flow fan or hot debris, and was probably the source of the satellite thermal anomaly. On 23 February an active lava flow or hot lahar was observed on the volcano's SW flank. Avalanches of hot, rubbly debris from this flow reached the sea and produced steam clouds at the shoreline.

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Anchorage Volcanic Ash Advisory Center (VAAC)


14 February-20 February 2001

The AVO reported that Cleveland volcano erupted explosively at 0600 on 19 February, producing an ash-and-steam cloud that was detected from the beginning of the eruption on GOES imagery and confirmed by pilot reports at 1310. Satellite imagery at 0945 showed that the cloud was in two sections; the lower section reached ~5.2 km a.s.l. and drifted SE of Cleveland, and the higher section reached 9.1-10.7 km a.s.l. and drifted to the N. By 1900 the cloud had extended at least 120 km to the N and drifted E towards Dutch Harbor, Akutan, and beyond. The National Weather Service via the Anchorage VAAC, and the Federal Aviation Administration, issued a volcanic ash advisory to divert aircraft away from the ash cloud. During 1200 to about 1600, light ash fell in the closest inhabited town to the volcano, Nikolski (~30 residents), 45 miles E of the volcano. The Anchorage VAAC reported that additional eruptions occurred through 1800. According to the AVO, explosive activity ended in the late afternoon and at 2130 a thermal anomaly was still visible on satellite imagery. Prior to the eruption the AVO had received pilot reports and photos of increased emissions on 2 February, but the reports could not be confirmed without ground-based monitoring instrumentation. The AVO warned that further eruptive activity could occur with little warning. Because Cleveland is not seismically monitored, the AVO did not assign a level of concern color code.

GOES images and animation of the 19 February ash cloud

Sources: US Geological Survey Alaska Volcano Observatory (AVO); Anchorage Volcanic Ash Advisory Center (VAAC); Reuters; Anchorage Daily News


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.

12/1985 (SEAN 10:12) Steam plume with little ash

04/1986 (SEAN 11:04) Steam plume with some ash

06/1986 (SEAN 11:06) Incandescent tephra

06/1987 (SEAN 12:06) Lava flow and ash emission from summit crater

07/1987 (SEAN 12:07) Incandescent fountains from summit vent

08/1987 (SEAN 12:08) Possible source of 10.6-km cloud; lava flow

05/1994 (BGVN 19:05) Single ash burst generates a plume to >10 km altitude

06/1994 (BGVN 19:06) Ashfall from 21 May eruption observed on the NE flank

01/2001 (BGVN 26:01) 19 February explosion sends ash up to 10 km

04/2001 (BGVN 26:04) Further eruptions and ash plumes during March 2001

09/2005 (BGVN 30:09) Minor eruptions during June-October 2005 after 4 years of quiet

01/2006 (BGVN 31:01) 6 February 2006 eruption on remote, non-instrumented island

06/2006 (BGVN 31:06) Ash plume on 23 May 2006 to over 6 km altitude

07/2006 (BGVN 31:07) Astronauts capture photo of 23 May eruption

09/2006 (BGVN 31:09) Short duration explosions during August-October 2006

02/2008 (BGVN 33:02) Thermal anomalies and minor explosions continue through February 2008

07/2008 (BGVN 33:07) Eruption on 21 July 2008; lava flows and ash plumes

11/2008 (BGVN 33:11) Explosive ash emission on 2 January 2008

10/2009 (BGVN 34:10) Two explosive ash emissions in June and October 2009

12/2009 (BGVN 34:12) At least three eruptions during 2009, with a possible fourth on 12 December

06/2010 (BGVN 35:06) Small ash eruptions during 25 May to early June 2010

05/2011 (BGVN 36:05) Thermal anomalies and possible plumes through mid-September 2010

08/2011 (BGVN 36:08) Dome growth during August-September 2011 seen evolving in radar data

01/2012 (BGVN 37:01) Amendments to BGVN reports 2001-2011

10/2013 (BGVN 38:10) Dome growth and destruction during 2012-2013




Bulletin Reports

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


12/1985 (SEAN 10:12) Steam plume with little ash

"About midday on 10 December, pilot Tom Madsen (president, Aleutian Air) noted an anomalous 400+ m-high eruption column over Mt. Cleveland from the ground at Nikolski, Umnak Island (about 65 km ENE of the volcano). The top of the vertical column had drifted at least 0.5 km to the N. The white eruption cloud probably consisted principally of steam with only minor amounts of ash, if any. Based on observations by Madsen, Mt. Cleveland has been steaming fairly continuously since at least 1982, when he began flying regularly from Dutch Harbor (Unalaska Island) to Atka (Atka Island). Reeder has received several reports about steam-blast and phreatomagmatic eruptions at Mt. Cleveland over the last several years."

Information Contacts: J. Reeder, Alaska Div. of Geol. and Geophys. Surveys.

04/1986 (SEAN 11:04) Steam plume with some ash

On 28 April, Thomas Madsen (president, Aleutian Air Ltd.) observed an eruption plume emerging from the summit of Mt. Cleveland. He first saw the grayish-white plume at about 1220, from 190 km to the E, estimating that it reached ~2,900 m altitude . . . and extended SW. The plume had definite dark streaks and swirls of ash. Passengers on a Peninsula Airways flight . . . at about 1900 reported that the eruptive activity had declined to minor steam emission.

Information Contacts: J. Reeder, ADGGS.

06/1986 (SEAN 11:06) Incandescent tephra

The crew of the ship Blackhawk, (Hap Heyden, Ron Saylor, Dave Weyl and Capt. Emil Lindal) observed eruptive activity . . . on the morning of 27 May. At 0100, while some 30 km E . . . , one of the crew members could see glow at the top of the volcano and smelled sulfur fumes.

From 11 km ESE . . . at about 0235, Heyden observed a crater ~60 m in diameter on the upper ESE flank. The back inside wall of the crater was visible. Lava rose to 30 m above the rim, then fell back into the crater. Weyl saw an ~10-m-wide glowing zone that extended from the crater at least 100 m down the SE flank, probably a lava channel. Glow from the crater seemed to be pulsating substantially. As the Blackhawk headed SW, at about 0450, Saylor detected a fog-like cloud that irritated his eyes and throat. They did not emerge from the fume cloud until they were S of Herbert Island, ~25 km SSW of the volcano. No ash was detected on the boat.

T. Madsen and John Reeder flew within 40 km of Mt. Cleveland on 10 July at about 1845 and 2115, observing minor steaming from the SE summit. Black ash blanketed the upper 650 m of the volcano, while the lower slopes were still covered with white snow.

Information Contacts: J. Reeder, ADGGS.

06/1987 (SEAN 12:06) Lava flow and ash emission from summit crater

On 19 June pilot T. Madsen (Aleutian Airways) observed minor bluish-brown ash rising to 2,000-2,500 m altitude and drifting SE for as much as 50 km. Later that day (about 1300) Madsen observed continued fine ash emissions. Fresh ash was seen on all flanks of the volcano but was concentrated on the ESE flank. Two or three large hot rocks fell from the summit onto the ESE flank during his observations.

Pilot Harold Wilson (Peninsula Airways) observed Mt. Cleveland several times between 22 and 29 June. At 1600 on 22 June a steam plume was rising ~300 m above the summit and fresh black ash covered most of the volcano; snow had fallen in the region in the last week. At noon the next day incandescent lava was visible in the cracks of a 30-m-diameter dome-like feature within the summit crater. A narrow lava flow extended down the ESE slope and ponded at the base of the volcano. Blocks were thrown to 30 m above the vent and steam rose ~450 m above the summit. Numerous photos were taken. The "dome" incandescence and steam emission remained visible through 26 June. On 27 June the volcano was obscured by steam and clouds. Wilson noted that the activity was the most intense he had ever seen at Mt. Cleveland since he began flying in the region in 1980.

Information Contacts: J. Reeder, ADGGS.

07/1987 (SEAN 12:07) Incandescent fountains from summit vent

On 22 July, H. Wilson (Peninsula Airways) observed an active lava fountain at 1700 and again at close range at 2100 (during daylight). He photographed an incandescent fountain, 20-30 m high and ~2.5 m wide, emerging from the summit-crater vent that had been active in June. A lava flow from this vent reached the base of the volcano in June but Wilson did not recognize an active summit lava flow during his 22 July overflights. A mound that had formed at the head of the June lava flow appeared to have grown slightly. Some steam and very minor ash was being emitted from the vent.

Information Contacts: J. Reeder, ADGGS.

08/1987 (SEAN 12:08) Possible source of 10.6-km cloud; lava flow

During at least five overflights between 6 and 10 August, H. Wilson (Peninsula Airways) observed incandescent lava and summit glow, but did not recognize any lava fountains or moving flows. High-pressure steam emission was occurring and steam drifted as far as 3 km from the summit. At about 1500 on 26 August, pilot T. Madsen (Aleutian Air) observed a 600-m-high ash and steam plume. Two days later, on 28 August at about 0930, Scott Kerr and Pete Galaktionoff heard a distant rumbling sound lasting ~15 seconds while camping on Kagamil Island (25 km NE of Mt. Cleveland, 120 km NE of Amukta). Overcast skies prevented observations. At 0944 that day the National Warning Center of the North American Air Defense Command (NORAD) issued a warning of a large eruption of Mt. Cleveland, after detecting a hot spot that morning at 52.78°N, 169.93°W through remote sensing. Steve Shivers (USGS Anchorage) recognized a WNW-trending plume on a NOAA 10 satellite image returned at 1030. The ~15-km plume was elongated WNW from a point ~15 km W of Mt. Cleveland. From more than 100 km away at about 1100, pilot Charles Nickerson (Reeve Aleutian Airways) reported that the plume, which appeared to be drifting WNW, reached 9-10.6 km altitude with about a 25 km upper radius, but the plume was by then apparently detached from its origin and the volcano that fed it is not certain. He estimated that the plume was just ENE of Amukta and W of Cleveland. Mt. Cleveland's summit appeared to be emitting a 300 m-high steam plume. At about 1200, Larry Conner (MarkAir) also observed the eruption plume from a point ~30 km S of Amukta, which was completely covered by clouds and not emitting a plume. At about 1400, pilot William Redmond (Peninsula Airways) observed unusual, thin, brown-tinted, cirrus layers beginning 65 km WNW of Mt. Cleveland at 2,400 m altitude and higher. The wind was blowing from the E.

Information Contacts: J. Reeder, ADGGS.

05/1994 (BGVN 19:05) Single ash burst generates a plume to >10 km altitude

A vigorous steam plume was observed by pilots on 29 April and by AVO observers on 10 May. No ash was observed on 10 May either in the plume or on the flanks of the volcano. A single ash burst on 25 May generated a plume that rose to ~10.5 km altitude according to two pilot reports between 1700 and 1800 in the afternoon. The plume was described as dark gray and moderately dense by one pilot. Weather clouds obscured the view from satellites immediately following the eruption, but NWS satellite imagery later showed a small volcanic cloud drifting NE over the Bering Sea at ~5 km altitude. Apparently the activity consisted of a single burst without a sustained eruption; no additional eruptive activity was reported through mid-June.

Information Contacts: AVO; J. Lynch, SAB.

06/1994 (BGVN 19:06) Ashfall from 21 May eruption observed on the NE flank

On 21 June, AVO observers noted a broad, black swath of material extending from within a few hundred meters of the summit well down the NE flank. A vigorous white steam plume was being driven by wind down the ESE flank. The debris was presumed to be ash from the small [25] May eruption. FWS personnel aboard the RV Tiglax had observed the black swath earlier in the week.

Information Contacts: AVO.

01/2001 (BGVN 26:01) 19 February explosion sends ash up to 10 km

At 0600 on 19 February workers at the Alaska Volcano Observatory (AVO) using satellite imagery detected an ash cloud emanating from Cleveland volcano. The eruption was apparently explosive (figure 1). According to images captured at 0945 the ash cloud had split and drifted in two directions; one traveled 120 km SE of the volcano and reached an altitude of over 5 km, while the other cloud drifted higher, traveled 100 km N, and rose to an altitude of over 9 km (figure 2). A volcanic ash advisory was first issued at 1040 on the same day indicating that ash was being carried E at a velocity of ~55 km/hour and had reached an altitude of over 10 km. Subsequent pilot reports and satellite data revealed a diminishing intensity of the ash issuing from Cleveland, although observers in Nikolski, 72 km to the E, reported ashfall initiating at 1200 and persisting through 1600. Explosive activity ended by late afternoon.

Figure 1. Cleveland on 21 February. The usually white, snow-covered flanks are shown darkened by ash from the eruption. Photo was taken by Burke Mees (PenAir pilot) and transmitted courtesy of AVO.
Figure 2. Composite of GOES images showing the progressive locations and evolution of the ash clouds erupted from Cleveland during 19-21 February. The initial image of the plume (far left) was taken at 0815 on 19 February approximately 2 hours after the eruption began (labeled "2/19/01, 1615 Z"). Over time the plume bifurcated, sent ash SE to an altitude of 6 km, and ash N and slightly W to an altitude of 9 km. Ash clouds rose to a maximum altitude of over 10 km (roughly "FL330," aviation shorthand for 33,000 feet) before dissipating. Times are listed in UTC (not local time). The image also highlights the importance of quickly relaying information from volcano observatories to airline dispatchers in order to keep pilots aware of potential ash along their routes. Only areas of detected ash are shown, and ash may be present elsewhere. Image noise has been removed for clarity. Courtesy of AVO.

AVO workers observed a persistent large thermal anomaly at the volcano, which indicated that further eruptions could occur at any time. Pilots flying near the volcano late on 21 February confirmed no further ash production, but one did observe steaming near the termination of a flow on the volcano's SW flank. The steaming was located where rubbly, apparently hot debris entered the sea, and could have been an active lava flow or a fan of debris; it likely explains the thermal anomaly detected in satellite images. A thermal anomaly continued to be detected as of 26 February, suggesting that low-level activity was still occurring. No level of concern color codes were assigned for Cleveland because AVO has no seismic monitoring stations at the volcano.

Even after the eruption ceased, the eastward drifting ash-and-steam cloud continued to be a hazard to aviators (figure 2). The SE portion of the plume approached the westernmost point of Umnak Island by 1030 on the day of the eruption, and the entire plume was carried farther E so that it reached Dutch Harbor and Akutan by 1900.

Satellite imagery at 0730 on 20 February showed the ash cloud as a band extending from S of Port Heiden to N of Nunivak Island. No ashfall was reported at Dutch Harbor, Port Heiden, or Dillingham, however.

By 0530 on 21 February the cloud could be seen on satellite imagery stretching from near Montague Island S about 150 km over the northern portion of the Gulf of Alaska. The ash band dissipated and became undetectable in satellite images by about 1700 on 21 February. A smaller ash cloud may also have drifted over interior Alaska reaching N of Fairbanks, but it became indistinguishable from weather clouds by the same time.

Reference. Miller, T.P., McGimsey, R.G., Richter, D.H., Riehle, J.R., Nye, C.J., Yount, M.E. and Dumoulin, J.A., 1998, Catalog of the historically active volcanoes of Alaska: U.S. Geological Survey Open-File Report 98-582, Alaska Volcano Observatory, Alaska, 1998. 104 p.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Anchorage Volcanic Ash Advisory Center (VAAC), 6930 Sand Lake Road, Anchorage, AK 99502, USA (URL: http://www.ssd.noaa.gov/VAAC/ OTH/AK/messages.html).

04/2001 (BGVN 26:04) Further eruptions and ash plumes during March 2001

As predicted in February 2001 (BGVN 26:01) by staff at the Alaska Volcano Observatory (AVO), Cleveland erupted again, sending up noteworthy plumes on both 11 and 19 March. The 11 March event produced an ash plume that reached a height of ~4.4-5.9 km above Cleveland's summit (figure 3). On 19 March, AVO detected an explosive eruption on satellite imagery that began at ~1430. According to images taken at 1830, the ash cloud was V-shaped with one portion extending 185 km to the E and the other extending ~200 km to the SE (figure 4). The National Weather Service estimated the top of the cloud to be at ~9.7 km altitude. At about 1900, an observer in Nikolski, ~70 km to the E of the volcano, reported an intense haze resulting from the ash that extended to the SE, but saw no local ashfall.

Figure 3. Color composite of LandSat images from the 11 March 2001 Cleveland eruption. The white outline shows the position of Chuginadak Island, hidden beneath the ash. Courtesy of Dave Schneider (AVO, USGS).
Figure 4. Sketch map illustrating ash area from Cleveland as of 2200 on 19 March 2001 (0600 on 20 March 2001 UTC). After an image by NOAA.

The Washington Volcanic Ash Advisory Center (VAAC) issued advisories for both eruptions based on information from GOES-10 infrared and multi-spectral imagery (figure 4). No ash was detected in satellite imagery reported in the subsequent advisory issued at 0500 on 20 March; the ash from the eruption had dissipated.

Volcanic unrest continued at Cleveland through 4 May. Pulses of volcanic tremor continued to be detected by an AVO seismic network 230 km to the E of the volcano. AVO personnel installed a temporary seismic-recording instrument at Nikolski in an attempt to verify that the source of the tremor was Cleveland. AVO had received no reports of significant volcanic activity from either pilots, nearby residents, or satellite remote sensors since the last eruption on 19 March.

Information Contacts: Tom Miller and Dave Schneider, Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Washington Volcanic Ash Advisory Center (VAAC), Washington, DC, USA (URL: http://www.ssd.noaa.gov/VAAC/washington.html).

09/2005 (BGVN 30:09) Minor eruptions during June-October 2005 after 4 years of quiet

Mount Cleveland produced significant ash plumes during March 2001 (BGVN 26:04). Volcanic unrest continued through 4 May 2001, and signals consistent with volcanic seismicity were detected by an Alaska Volcano Observatory (AVO) seismic network 230 km E. By the end of May, neither eruptive activity nor thermal anomalies were observed. Until July 2005, no alert level was assigned, and AVO monitoring produced no reports on Cleveland.

Cleveland lacks a real-time seismic network. Accordingly, even during times of perceived quiet there is an absence of definitive information that activity level is at background. AVO's policy for volcanoes without seismic networks is to not get assigned a color code of Green.

Satellite imagery of Cleveland taken during 24 June to 1 July 2005 showed increased heat flow from the volcano and a possible debris flow. AVO stated that although observations were inhibited by cloudy weather, they indicated the possibility of increased volcanic activity. AVO did not assign a Concern Color Code to Cleveland due to the lack of seismic monitoring and limited satellite observations.

Satellite images during 1-8 July showed increased heat flow, thin ash deposits, and possible debris flows extending ~ 1 km down the flanks from the summit crater. AVO assigned a Concern Color Code of Yellow on 7 July. On 18 July satellite imagery showed steam emanating from Cleveland's summit and evidence of minor ash emissions. Meteorological clouds obscured Cleveland during the third week of July. During 22-29 July satellite images showed minor steaming from the summit, possible fresh localized ash deposits, and a weak thermal anomaly.

On 4 August satellite images showed a thermal anomaly. On 27 August AVO reduced the Concern Color Code at Cleveland from Yellow to "Not Assigned" because there had been no evidence of activity since a thermal feature was observed on satellite imagery from 11 August. A thermal feature was detected on several satellite images obtained on 31 August, and one on 19 September, but there was no evidence of eruptive activity.

On 7 October, AVO raised the Concern Color Code to Orange after detecting a small drifting volcanic ash cloud. The cloud was seen in satellite data at a spot ~ 150 km ESE of Dutch Harbor at 1700 UTC. Based on data from a regional seismometer at Nikolski, AVO concluded that the ash came from a small Cleveland eruption at approximately 0145. AVO, in consultation with the National Weather Service, estimated the top of the ash cloud to be no more than 4,600 m altitude. The ash cloud dissipated and was not detected via satellite after 1800 UTC. Three days passed during which there were no new observations of eruptive activity at Cleveland from satellite data, pilots, or ground-based observers. Accordingly, on 10 October the Concern Color Code was reduced to Yellow.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Washington Volcanic Ash Advisory Center (VAAC), Washington, DC, USA (URL: http://www.ssd.noaa.gov/VAAC/washington.html).

01/2006 (BGVN 31:01) 6 February 2006 eruption on remote, non-instrumented island

According to the Alaska Volcano Observatory (AVO), Mount Cleveland, a volcano on an uninhabited island in the central Aleutian chain, erupted at 0757 on 6 February 2006, sending a cloud of ash to 6.7 km (22,000 ft) altitude. Officials at AVO issued a Code Red warning for the volcano because the ash cloud was near a level where it could interfere with jet traffic, said Chris Waythomas, a U.S. Geological Survey geologist. There were no reports of falling ash. The nearest community is Nikolski, a tiny Aleut village of 31 people 73 km E of the volcano.

Cleveland's last major eruptive period was in March 2001 when three explosions occurred and the volcano produced significant ash plumes (BGVN 26:04). Discussion of that episode was renewed briefly at the end of the Augustine report in this issue (BGVN 31:01). That discussion (and cited references) noted that the ash cloud from a Cleveland eruption on 19 February 2001 had a modeled path that carried the cloud S, passing over Northern California. Two days after the eruption, aviators flying near San Francisco, California, smelled sulfurous gases, presumably from the Cleveland eruption. There were also minor ash emissions from July to October 2005 (BGVN 30:09).

AVO downgraded the level of concern color code for Cleveland from Red to Orange on 7 February 2006 at 1655 hours. No new ash emissions or thermal anomalies have been detected in clear to partly cloudy satellite views from the morning of 8 February. AVO noted that Cleveland does not have a real-time seismic network and therefore it is unable to monitor seismic changes.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (SAB), NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/).

06/2006 (BGVN 31:06) Ash plume on 23 May 2006 to over 6 km altitude

Since an ash cloud was detected on 6 February 2006 (BGVN 31:01), observers have documented two brief spurts of activity. On the morning of 2 May beginning at 0101, a thermal anomaly and continuous plume were seen on satellite imagery. The plume extended ~ 50 km SW and was visible on imagery for ~ 6 hours. Satellite data suggested a maximum height of ~ 1 km altitude There was no indication of ash in the cloud. No further activity was detected for several weeks after the 2 May plume. In this interval Cleveland was not assigned a Concern Color Code because there is no real-time seismic network at the volcano.

The second episode took place on 23 May 2006. AVO reported that an astronaut aboard the International Space Station observed an ash plume from Cleveland at 1500. At 1507 satellite imagery showed a plume that drifted SW and reached an altitude of ~ 6.1 km. At 1700, an image showed the detached ash plume 130 km SW of Cleveland. The Concern Color Code was raised to Yellow.

The ash plume had mostly dissipated by 24 May. On 26 May, AVO downgraded the Concern Color Code from Yellow to "Not Assigned."

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), the Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and the Alaska Division of Geological and Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Earth Observatory, National Aeronautics and Space Administration (NASA) (URL: http://earthobservatory.nasa.gov/NaturalHarards/).

07/2006 (BGVN 31:07) Astronauts capture photo of 23 May eruption

On 23 May 2006, the Alaska Volcano Observatory (AVO) received a report from the International Space Station indicating that a plume was observed moving W from Cleveland volcano at 2300 UTC (BGVN 31:06). A photograph of the plume taken from the International Space Station was released by the National Aeronautics and Space Administration (NASA) (figure 5).

Figure 5. Eruption of Mount Cleveland on 23 May 2006 as photographed from the International Space Station at an orbital altitude of ~ 400 km. The photograph (N at the top; Carlisle Island to the NW) shows the ash plume moving SW from the summit. Banks of fog (arcuate clouds at upper right) are common features around the Aleutian Islands. The event proved to be short-lived; ~ 2 hours later, the plume had completely detached from the volcano. Courtesy of Jeffrey N. Williams, Flight Engineer and NASA Science Officer, International Space Station Expedition 13 Crew, NASA Earth Observatory.

Starting at about 2300 UTC, just before this image was taken, Cleveland underwent a short eruption. The volcanic plume was seen in Advanced Very High Resolution Radiometer (AVHRR) polar-orbiting satellite data beginning from 2307 UTC. By 0100 UTC on 24 May the ash plume had detached from the vent and was approximately 130 kilometers SW of the volcano. Satellite data showed a cloud height of about 6.1 km asl (table 1). The plume was no longer detectable in satellite imagery by 0057 UTC on 25 May. In response to the event, AVO raised the Level of Concern Color Code to 'Yellow.'

Table 1. Satellite observations of ash plume from Cleveland volcano. Courtesy of the Washington Volcanic Ash Advisory Center (VAAC).

    Date and Time (UTC)    Plume altitude    Direction and speed

    24 May 2006 (0200)         8.2 km        SW at 55 km/hour
    24 May 2006 (0800)         6.7 km        SW at 37-46 km/hour
    24 May 2006 (1400)         6.1 km        W at 37-46 km/hour

The last eruption of Cleveland was 6 February 2006 (BGVN 31:01). Since 24 May 2006, no new information about ash emissions had been received, nor have indications of continuing activity been detected from satellite data for the volcano. This short-lived event was typical of recent Cleveland activity. On 7 August 2006, AVO downgraded the Level of Concern Color Code for Cleveland from 'Yellow' to 'Not Assigned." Because Cleveland is not monitored with real-time seismic instrumentation, during intervals of repose it does not receive an assignment of Color Code 'Green,' but instead is left 'Not Assigned.'

Information Contacts: National Aeronautics and Space Administration (NASA) Earth Observatory (URL: http://earthobservatory.nasa.gov/); Washington Volcanic Ash Advisory Center (VAAC) (URL: http://www.ssd.noaa.gov/VAAC/washington.html); Jeffery Williams, NASA, ISS Crew Earth Observations and the Image Science & Analysis Group, Johnson Space Center 2101 NASA Parkway, Houston, TX 77058, USA.

09/2006 (BGVN 31:09) Short duration explosions during August-October 2006

Cleveland's commonly observed activity consisting of short duration explosions, such as those seen earlier in the year on 6 February 2006 (BGVN 31:01) and on 23 May 2006 (BGVN 31:07), continued during August and October 2006. This report will cover the 24 August and 28 October eruptions.

At 1955 on 24 August a brief eruption was seen by mariners on a passing ship. The eruption was unconfirmed by satellite data. Video footage sent to the Alaska Volcano Observatory (AVO) on 28 August showed that an ash cloud rose to an approximate altitude of 3 km and produced minor ashfall. Shortly after the eruption, minor steaming was observed from the vent on additional footage. In response to the eruption, the AVO raised the level of Concern Color Code from 'unassigned' to 'Yellow' on 7 September. A weak thermal anomaly in the summit crater was present in subsequent satellite images.

Clouds obstructed visibility through most of September and October.

A pilot reported that a minor eruption started at 1345 on 28 October. Satellite data confirmed the presence of an ash cloud drifting ENE of the volcano. The height of the cloud was estimated at an altitude of 6 km using the satellite imagery. One pilot reported the plume top at an altitude of 9 km. The AVO raised the alert level to 'Orange' during 28-29 October. On 30 October the AVO lowered the level to 'Yellow' because of no further evidence of activity.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA; Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA; and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/).

02/2008 (BGVN 33:02) Thermal anomalies and minor explosions continue through February 2008

Our previous reports on Cleveland discussed short duration explosions on 6 February 2006 (BGVN 31:01), 23 May 2006 (BGVN 31:07), and on 24 August and 28 October 2006 (BGVN 31:09).

We received no further reports on Cleveland until June 2007. On 12 June, steam emissions were observed. The plume rose to an altitude of 3.7 km and drifted SE for 200 km. On 17 June, satellite imagery showed a significant thermal anomaly. Low level eruptive activity was suggested. No ash plume was detected. On 26 June, satellite imagery showed another thermal anomaly. On 20 July, the Alaska Volcano Observatory (AVO) raised the Alert Level from Advisory to Watch and the Aviation Color Code from Yellow to Orange, based upon an intense thermal anomaly in the crater and an associated steam-and-gas plume observed on satellite imagery. Three small SO2 clouds produced by small explosions on 20 July were detected in OMI satellite data. Weak thermal activity was observed by satellite imagery throughout the month.

On 27 July AVO noted that low-level eruptive activity continued. Photographs from 27 July and a pilot report from 2 August indicated fresh volcanic ejecta on the slopes and summit. The E portion of Chuginadak Island was dusted with ash on 3 August. AVO lacks a local seismic system at the volcano was thus unable to track local volcanic earthquakes.

Thermal anomalies continued to be detected on satellite imagery, although clouds obscured satellite and web camera views of the volcano on most days during August through 11 September. A few clear views of the crater during this time revealed multiple thermal anomalies at the summit, indicating that low-level eruptive activity continued.

On 6 September, AVO lowered the Volcanic Alert Level for Cleveland from Watch to Advisory and the Aviation Color Code from Orange to Yellow, based on the observation that since late July, ash and gas plumes had been absent in satellite imagery and no reports of activity had been received. On 20 November the last weak thermal anomaly was observed for the year.

At 1200 on 17 January 2008, minor ash emission was detected, which drifted N. The plume height could not be determined. Thermal anomalies were found in the satellite imagery later that day. According to the AVO, on 8 February, during a break in the cloud cover, satellite imagery detected a diffuse ash plume extending about 12 km SE at an altitude below 1.5 km. Later that day AVO received pilot reports of a diffuse ash plume that rose to an altitude of 6.1 km and, according to satellite imagery, drifted NW. Due to the increased activity, the Volcanic Alert Level was raised to Watch and the Aviation Color Code was raised to Orange. During 10-11 February, a feeble thermal anomaly was marginally visible on satellite imagery.

On 12 February, the Volcanic Alert Level was lowered back to Advisory and the Aviation Color Code was lowered to Yellow. This occurred in response to the observation that minor eruptive activity appeared to have subsided and no further evidence of ash emission had been reported.

On 15 February, a minor explosion from Cleveland produced a small, diffuse ash plume that rose to an altitude of below 3 km and drifted NW. On 16 February, a brief explosion occurred. On 22 February, satellite imagery detected a low-level ash plume that drifted about 300 km SE. On 23 February, satellite imagery revealed a thermal anomaly. On 29 February, satellite imagery detected a weak thermal anomaly and a small ash plume that rose to an altitude of below 3 km. On 15, 27, and 30 March, weak thermal anomalies were detected. As of 4 April 2008, Cleveland remains at Advisory and the Aviation code Yellow.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA, the Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and the Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/); Volcanic Emissions Group, Ozone Monitoring Instrument (OMI)-Total Ozone Monitoring Spectrometer (TOMS), Joint Center for Earth Systems Technology, University of Maryland Baltimore County (UMBC), and NASA Goddard Space Flight Center (URL: http://toms.unbc.edu/).

07/2008 (BGVN 33:07) Eruption on 21 July 2008; lava flows and ash plumes

Minor explosions were reported from Cleveland volcano on 15 and 29 February 2008 Cleveland (BGVN 33:02); such events have been typical during the last several years. This report discusses subsequent behavior and observations into late August, including thermal anomalies, explosions, ash plumes, and an inferred lava flow.

AVO noted that during the two weeks prior to 9 May 2008, an increasing number of thermal anomalies were visible on satellite imagery. On 7 May, a small ash plume rose to an altitude of below 4.6 km. Also, around the same time, a ship N of Nikolski on Umnak Island (~ 75 km ENE) reported receiving a dusting of ash (figure 6).

Figure 6. Map of the Aleutian Islands focused around Cleveland volcano. From E to W, the noted settlements are Atka, Nikolski, Fort Glenn, Unalaska/Dutch Harbor, and Akutan. Courtesy of the Alaskan Division of Geological and Geophysical Surveys.

During June and early July 2008, satellite and webcam views were mostly obscured by clouds and fog, and AVO received no reports of eruptive activity. Satellite analysts noted a minor thermal anomaly on 8 June.

On 21 July, AVO raised the alert level/aviation color code for Cleveland to Watch/Orange based on reports from pilots and observers on fishing boats. Reports from fishing boats indicated that an eruption started at about 1200 and ash near sea level may have drifted NW. Pilots reported that an ash-and-steam plume rose to altitudes of ~ 4.6-5.2 km and drifted SE.

Satellite imagery for 22 July revealed a steam plume possibly containing some ash drifting more than 50 km ESE. It reached altitudes of 3-6 km. Thermal anomalies led analysts to infer a possible lava flow. Also, in harmony with this interpretation, on 22 July the MODVOLC algorithm registered its first alert thus far in 2008 (3 pixels) and near-daily alerts followed as late as 29 July (table 2).

Table 2. Thermal anomalies ("alerts") at Cleveland registered by the MODIS satellite as processed by the MODVOLC algorithm during the interval 1 January-9 September 2008. The only recent alerts during that interval were during the period of 22-29 July. Courtesy of Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System.

    Date (UTC)    Time (UTC)    Pixels    Satellite

    22 Jul 2008    1255           3         Aqua
    23 Jul 2008    0010           3         Aqua
    24 Jul 2008    0840           2         Terra
    24 Jul 2008    1245           3         Aqua
    24 Jul 2008    1420           5         Aqua
    27 Jul 2008    1315           1         Aqua
    27 Jul 2008    2240           1         Terra
    29 Jul 2008    0855           1         Terra

AVO reported that satellite views were hindered on 23 July due to cloud cover. On 24 July, a low-level ash plume and a strong thermal anomaly were noted near the summit. This thermal anomaly again suggested the presence of an active lava flow. The MODIS measurements shown in table 2 for 24 July indicated several thermal anomalies to the W of the cone and pixels that are displaced downslope, E of the cone, several almost reaching the ocean. The thermal anomalies continued to be detected during 26-28 July, and possible ash plumes drifted SE, E, and NE at altitudes of 3-6.1 km during 27-29 July.

According to David Schneider of AVO, the MODVOLC algorithm has a higher trigger threshold than an analyst and MODVOLC also has fewer observations each day since it only uses MODIS satellite data. AVO uses MODIS, AVHRR, and GOES satellites to reduce the chance of missing thermal anomalies due to cloud cover. Both MODVOLC and AVO use mid-IR data (in the 3.0 to 3.5 micron range) to detect high temperature thermal anomalies.

AVO reported that thermal anomalies detected at Cleveland's summit by various satellites during 30 July-5 August 2008 also suggested the presence of an active lava flow. The anomaly on 30 July extended about 6-9 km. On 31 July, a diffuse plume drifted less than 20 km NE, N, and NW at an altitude of 6.1 km. The plume was seen from an airplane on 1 August.

On 5 August, thermal anomalies appeared on the W, S, and SE flanks. They possibly indicated the presence of pyroclastic flows or hot lahars. On 6 August 2008, AVO reported that the thermal anomalies noted at Cleveland's summit and on the W, S, and SE flanks had decreased in intensity since first noted on 21 July, indicating that the lava flows slowed or stopped. The hazard status was lowered to Yellow/Advisory. During 7-10 August 2008, a weak thermal anomaly at Cleveland's summit was intermittently visible when not obscured by clouds and drifting ash from Kasatochi (~ 390 km WSW).

On 11 August, thermal anomalies on satellite imagery again indicated that lava flowed down the flanks. On 12 August an ash plume rose to an altitude of 7.6 km and drifted 100 km SW. Cloud cover prevented satellite observations during 13-26 August, although a possible thermal anomaly was present on 24 August. On 11 August the hazard status rose to Orange/Watch, but on 25 August it dropped to Yellow/Advisory.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), the Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and the Alaska Division of Geological and Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; 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/).

11/2008 (BGVN 33:11) Explosive ash emission on 2 January 2008

Satellite images acquired during the night of 23 December 2008 showed a persistent thermal anomaly near the summit of Cleveland, a stratovolcano forming the western half of the remote and uninhabited Chuginadak Island in the E-central Aleutian Islands. Cloud cover prevented satellite observations during 25-27 December, but a small thermal anomaly was observed on 28 December 2008. The Alaska Volcano Observatory (AVO) raised the aviation color code to Yellow and the alert level to Advisory on 24 December 2008.

AVO reported that on the morning of 2 January 2009, a short-lived but explosive ash emission occurred. The resulting plume reached to an altitude of ~ 6 km. The plume was first observed in a satellite image obtained at 1645 UTC and was visible in subsequent images for several hours. The plume drifted ~ 240 km ESE, but then dispersed rapidly and could no longer be detected. Satellite views of the volcano were obscured by clouds most of the week; however, a minor thermal anomaly was observed in satellite views of the summit on the morning of 4 January. During this event no active lava flows were observed, as compared with events of July-August 2008 (BGVN 33:07).

Cleveland lacks seismic instrumentation; satellite data and pilot reports are the primary information sources. Thermal anomalies were absent after the cluster of events during 22-29 July 2008 (BGVN 33:07).

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), the Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and the Alaska Division of Geological and Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA.

10/2009 (BGVN 34:10) Two explosive ash emissions in June and October 2009

As previously reported (BGVN 33:11) , the Alaska Volcano Observatory (AVO) had raised the aviation color code for Cleveland on 24 December 2008 to Yellow and the alert level to Advisory, following a thermal anomaly near the summit that was present for two days. The anomaly was occasionally observed into early January 2009. On 2 January, a short-lived ash explosion produced an ash plume that rose ~ 6 km and drifted ~ 240 km ESE before dissipating.

A small explosive eruption on 25 June 2009 sent an ash cloud rose to an estimated altitude of 4.6 km, which quickly detached from the volcano and drifted S. Another small and brief explosive eruption occurred on 2 October. A small detached ash cloud rose to maximum altitudes of 4.6-6.1 km and drifted ~ 600 km NE, dispersing over the Bering Sea. No further activity was detected through 19 October, so the Alert Levels were lowered to "Unassigned." Cleveland is not monitored by a real-time seismic network, thus the levels "Green" or "Normal" do not apply because background activity is not defined.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), the Geophysical Institute, University of Alaska, P.O. Box 757320, Fairbanks, AK 99775-7320, USA (Email: eisch@dino.gi.alaska.edu), and the Alaska Division of Geological and Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (Email: cnye@giseis.alaska.edu).

12/2009 (BGVN 34:12) At least three eruptions during 2009, with a possible fourth on 12 December

Cleveland, an Aleutian Islands volcano situated almost 1,500 km S of the E margin of the Bering strait, had multiple short-duration ash-bearing explosive eruptions in 2009. The first of these documented eruptions took place on 2 January 2009 (BGVN 33:11). The next two documented ash-bearing eruptions occurred on 25 June and 2 October 2009 (BGVN 34:10). As stated in those previous issues, thermal anomalies were common in satellite data as reported by the Alaskan Volcano Observatory (AVO).

Previously not reported was a possible fourth 2009 eruption, which took place on 12 December. It seemingly generated a diffuse ash plume, an event detected a few days later in satellite imagery (figure 7). AVO had also lowered the hazard status on 12 December to "Unassigned," a level that results from the lack of a nearby seismic receiver and the consequent inability to define background seismicity. As of late January 2010, further activity at Cleveland was absent and no further reports were issued.

Figure 7. A MODIS satellite image of Cleveland volcano and vicinity captured at 2237 UTC on 12 December 2009 (brightness temperature difference from Channel 31 minus Channel 32). The plume (at tip of horizontal arrow) was judged as likely due to an eruption but this was not certain. N is towards the top and for approximate scale, the adjacent (Nikolski) island outlined to the E is ~100 km long (for other maps, see BGVN 33:07 and 26:01). Courtesy of John Dehn, AVO (arrows added).

John Dehn of AVO provided more details regarding the discovery and interpretation of the 12 December plume (figure 7). It was initially detected by David J. Beberwyk at the Air Force Weather Agency (AFWA). The information was passed to AVO and distributed to staff on 14 December. After looking at the imagery, they announced in log entries on 15 December that they had possibly missed the faint signal in their daily reporting. Dehn was "pretty confident that this [was] real but the signal is comparable to weather systems."

Dehn went on to note that "Cleveland is known for these small events, and whether we catch them is up to the fortuitousness of a satellite pass and good weather. No further activity was reported, though [AVO's] Rick Wessels noted that a MODIS image from a few hours later shows possible dark deposits on the NW side of the summit. The summit of the volcano has typically had dark deposits on the snow in recent years as we've seen on the webcam, satellite imagery and observer reports so this [was] not conclusive."

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA; Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA; and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/).

06/2010 (BGVN 35:06) Small ash eruptions during 25 May to early June 2010

The Alaska Volcano Observatory (AVO) noted four explosive events at Cleveland in 2009, the last causing a diffuse ash plume on 12 December (BGVN 34:12). Additional small ash clouds have since been observed during late May and early June.

On 25 May 2010, AVO warned that thermal anomalies observed in satellite data over the past few days suggested another period of unrest. In the past, thermal anomalies at the summit have been followed by moderate ash bursts, sometimes to aircraft flight levels. An ash cloud was visible in a satellite image at 0756 on 30 May. It rose to an altitude of ~ 4.9 km and drifted to the SW. At the time of the satellite image, the cloud was detached, and it was estimated that the emission had occurred several hours earlier. The event was interpreted as a short-lived ash emission without signs of further activity. Satellite images from 31 May also showed minor deposits on the upper flanks, and a 1 June image showed debris flow deposits down the E flank and ashfall deposits on the SW flank. Small plume were seen rising from the crater on 1 and 4 June (figure 8). A weak thermal anomaly detected on 2 June suggested continuing low-level ash emission.

Figure 8. The Advanced Land Imager (ALI) on NASA's Earth Observing-1 (EO-1) satellite captured this image of Cleveland on 4 June 2010. Clouds nearly surround the snow-capped volcano, which is striped with dark ash and debris flow. A small, faint plume rises from the summit. Courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team and NASA Earth Observatory.

From 5-9 June 2010, satellite images of Cleveland were mostly obscured by clouds, and AVO received no reports of ash emission. On 10 June, a partly cloudy satellite view lacked evidence of ash emissions or thermal anomalies.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA; Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA; and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/NaturalHazards); NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team (URL: http://asterweb.jpl.nasa.gov/).

05/2011 (BGVN 36:05) Thermal anomalies and possible plumes through mid-September 2010

Occasional small ash eruptions occurred at Cleveland during 2009 through early June 2010 (BGVN 35:06). Mild restless behavior continued at least into mid-September 2010 but it was uncertain whether ash had been emitted.

Table 3 compiles key observations and alerts for Cleveland volcano during mid-June through 31 March 2011. The Alaska Volcano Observatory (AVO) reported that thermal anomalies were sometimes visible and sometimes absent on satellite imagery. One or two ash plumes may have also been emitted. Accordingly, these observations caused authorities to raise and lower the Volcano Alert Level and Aviation Color Code (table 3). Volcano seismicity was absent because Cleveland lacks a real-time seismic network. The thermal anomalies and possible plumes could both could stem from steam emissions (see AVO statement at bottom of this report).

Table 3. Reports of activity at Cleveland based on satellite imagery during 10 June 2010 through 31 March 2011. Also shown are Volcano Alert Level and Aviation Color Code fluctuations based on that activity. Courtesy AVO.

DateObservation based on satellite imageryVolcano Alert LevelAviation Color Code
10 June 2010 Advisory Yellow
11 June 2010 Unassigned Unassigned
16 Aug-1 Sept 2010 Thermal anomalies visible on most days
26 Aug 2010 Advisory Yellow
7-8 Sept 2010 Clear-weather views showed no thermal anomalies or recent deposits on the flanks
8 Sept 2010 Unassigned Unassigned
11 Sept 2010 Thermal anomaly visible
12 Sept 2010 Possible ash plume rose to ~7.6-km altitude and drifted E
12 Sept 2010 Advisory Yellow
13-15 Sept 2010 Thermal anomalies visible
16-24 Sept 2010 Cloud cover prevented views
25-26 Sept 2010 Weak thermal anomaly visible
27-28 Sept 2010 Cloud cover prevented views
31 March 2011 Unassigned Unassigned

On 12 September 2010, a possible ash plume was visible in satellite imagery; it rose to an estimated altitude of 7.6 km and drifted E. A 14 September image showed a dense white plume issuing from Cleveland (figure 9).

Figure 9. Image of a small, dense, compact white plume issuing from Cleveland at 1431 on 14 Sept 2010, captured by the GeoEye IKONOS satellite. In color versions of the image, red highlights areas of vegetation detected by the near-infrared channel. Photographed/created by Rick Wessels. Image processed by AVO/USGS; copyright 2010 by GeoEye. Courtesy AVO.

On 31 March 2011, AVO lowered the Volcano Alert Level and the Aviation Color Code to Unassigned, noting that no eruptive activity had been confirmed during the previous few months. No significant thermal anomalies or ash deposits on snow were observed in satellite imagery.

In its 31 March 2011 report, AVO stated that "Cleveland experiences frequent episodes of low-level unrest; the summit crater at Cleveland often emits visible plumes of water vapor and possibly small quantities of volcanic gas. Heat associated with this process can produce occasional weak thermal anomalies detected by satellite; however, these do not always indicate eruptive activity has occurred or is imminent."

AVO also stated, in an earlier report, that low-level ash emissions at Cleveland occur frequently and also do not necessarily mean that a larger eruption is imminent.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA; Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA; and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/).

08/2011 (BGVN 36:08) Dome growth during August-September 2011 seen evolving in radar data

Figure 10 shows the location of Cleveland volcano, the scene of significant changes in dome morphology in August and September 2011. On 31 March 2011 the Alaska Volcano Observatory (AVO) lowered the Volcano Alert Level and the Aviation Color Code for Cleveland to Unassigned, noting that no eruptive activity had been confirmed during the previous few months (BGVN 36:05). Cleveland lacks a real-time seismic network, which means AVO cannot track local earthquakes and estimate volcanic unrest. AVO notes that short-lived explosions with ash clouds that could exceed 6.1 km altitude can occur without warning and may go undetected on satellite imagery for hours. Low-level ash emissions at Cleveland occur frequently and do not necessarily mean a larger eruption is imminent. AVO continues to monitor the volcano using satellite imagery.

Figure 10. Location of Cleveland volcano and other Aleutian volcanoes with respect to nearby cities and towns. Map created by Janet Schaefer and provided courtesy of AVO and the Alaska Division of Geological & Geophysical Surveys (ADGGS).

AVO reported that on 20 July 2011 the Volcano Alert Level for Cleveland was raised to Advisory, and the Aviation Color Code was raised to Yellow due to thermal anomalies visible in satellite imagery during 19-20 and 22 July 2011. Cloud cover prevented observations during 21 and 23-26 July.

During the week of 25-31 July 2011 elevated but weak thermal anomalies were observed in satellite images of during periods of clear weather. AVO found no evidence of ash emissions or eruptive activity. Observations on 29 July 2011 showed a small lava dome ~ 40 m in diameter in the summit crater, apparently formed since 19 July based on measured thermal anomalies. Observations on 2 August revealed growth of the lava dome from ~ 40 to 50 m in diameter. In response, AVO raised the Aviation Color Code to Orange and the Alert Level to Watch.

An animated sequence of satellite radar images revealed what was hard to see through persistent weather clouds. They portrayed dynamic growth of the lava dome during early August through at least late September 2011 (figure 11).

Figure 11. A sequence of satellite radar images showing Cleveland volcano's summit crater and growth of its lava dome for 7, 18, and 29 August, and 9 and 20 September 2011. The radar data are from the TerraSAR-X sensor (wavelength 31 mm, frequency 9.6 GHz). The summit crater is ~ 200 m across. Note that satellite radar images have inherent topographic distortion (eg. foreshortening and layover) due to the manner in which they are collected. Image copyrighted in 2011 by the German Remote Sensing Data Center (DFD) and German Aerospace Center (DLR). Provided courtesy of Dave Schneider and Zhong Lu (Alaska Volcano Observatory, AVO) and the U.S. Geological Survey (USGS).

AVO reported weak thermal anomalies in satellite imagery during 2-3, 5, 7-9, and 13-14 August when cloud cover was limited or absent. They noted that a scientist flying N of the volcano on 14 August observed small white puffs of steam rising 30-60 m above the summit, even though most of the volcano was obscured by clouds.

During 17-23 August cloud cover over Cleveland prevented observations of the summit crater. On 21 August AVO noted that a weak, 1-pixel thermal anomaly was observed in a recent satellite view during a cloud break. On 30 August 2011, satellite observations during the previous two weeks indicated a pause in lava-dome growth. AVO lowered the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow. Cloud cover prevented views of the summit crater during 31 August-2 September, but a thermal anomaly at the summit was observed during 3-5 September.

Observations on 6-7 September 2011 indicated that the lava dome had resumed growth (figure 11), reaching 120 m in diameter and filling the floor of the crater. AVO again raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. Although cloud cover often prevented observations of Cleveland during 7-12 September, a thermal anomaly on the lava dome was visible during 8-9 and 12 September, and a possible anomaly was visible on 10 September. These anomalies suggested that lava-dome growth was continuing, although no activity was observed in partly cloudy satellite images during 12-17 September. During 17-18 September a thermal anomaly was detected in imagery.

A report on 20 September noted that recent observations revealed the lava dome had grown to ~165 m in diameter. The dome remained contained within the ~ 200-m-diameter crater at Cleveland's summit, having advanced to ~ 20 m below the E crater rim.

During 20-22 September no observations of elevated surface temperatures or ash emissions from Cleveland were visible in partly cloudy satellite images. Elevated surface temperatures were observed in satellite images during 23-24 September, suggesting that the lava dome eruption was continuing. On 24-25 September 2011 elevated surface temperatures were absent in several clear satellite images. Cloud cover prevented observations on 26 September. Satellite views detected continued elevated summit temperatures over the period 27-28 September 2011. Satellite data also suggested ongoing eruption as the lava dome continued growing.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey (USGS), 4200 University Drive, Anchorage, AK 99508-4667 USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys (ADGGS), 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.dggs.alaska.gov/).

01/2012 (BGVN 37:01) Amendments to BGVN reports 2001-2011

Our last report on Cleveland volcano, August 2011 (BGVN 36:08), described lava dome growth in August-September 2011. This report first addresses late 2011 to early 2012 observations, and then presents some amendments to Bulletin reports over the last decade.

Late 2011-early 2012. According to the Alaska Volcano Observatory (AVO), by the first week of October 2011 satellite images showed the lava dome was within 10 m of the crater rim on the SW and ENE sides of the crater. On 23 October, a TerraSAR-X satellite radar image of Cleveland showed no discernable growth in the lava dome over the course of the past several weeks. Instead, the 23 October image showed deflation or collapse of the dome.

On 3 November 2011, citing lack of dome growth evident in satellite images, AVO lowered both the Aviation Color Code to YELLOW and the Alert Level to ADVISORY. Throughout November, weather permitting, AVO continued to observe thermal anomalies and steam plumes in satellite imagery, consistent with cooling of the emplaced hot dome. Observations in early December 2011 showed continued deflation and cooling of the lava dome, which was about 1x106 m3 in volume.

On 29 December 2011, AVO observed in satellite imagery a detached, drifting ash cloud at an altitude of ~4.6 km and ~80 km ESE of Cleveland. Ground-coupled airwaves from an explosion were also detected at the distant Okmok seismic network, placing the time of explosion at 1312 (UTC) on 29 December 29.

Based on the presence of an ash cloud, on 29 December AVO raised the aviation color code to ORANGE and the alert level to WATCH. On 30 December, with no new explosive activity, AVO lowered the aviation color code to YELLOW and the alert level to ADVISORY. Subsequent satellite images showed that the 25 December (recognized in retrospective data analysis) and 29 December explosions had largely removed the dome.

On 30 January 2012, satellite data showed another small dome within the summit crater, which measured ~ 40 m in diameter by 30 January. On 31 January, AVO raised the aviation color code to ORANGE and the volcano alert level to WATCH. No observations of elevated surface temperatures or ash emissions from Cleveland were noted during 15-21 February. On 17 February, AVO reported that partly-cloudy satellite observations over the past week revealed that the current lava dome had grown to about 60 m in diameter and occupied a small portion of the approximately 200-m diameter summit crater. On 19 February an elevated surface temperature was detected in satellite images. As of this date, there is no real-time seismic monitoring network on Mount Cleveland.

Amendments to Bulletin. According to Diefenbach, Guffanti, and Ewert, (2009), “During the past 29 years, 43 volcanoes within the United States have produced 95 eruptions and 32 episodes of unrest. More than half of the 30 eruptive volcanoes have erupted two or more times. The majority (77 percent) of U.S. eruptions has occurred in Alaska. Akutan volcano in Alaska has produced the most eruptions (11) in the past 29 years, followed by Veniaminof (10), Cleveland (9), and Pavlof (8).”

Because of the relative importance of Cleveland in the Aleutian chain as a source of active volcanism along a busy commercial airline route, we revisited the AVO web site recently to compare information available with that which we used to prepare the Bulletin in the past. As a prelude to this section, table 4 lists Cleveland eruptions reported by the AVO during 2001-2012 and the issues of the Bulletin covering a particular event.

Table 4. Dates of significant eruptions as reported by the AVO web site for Cleveland from January 2001 through January 2012, and related BGVN reports covering the respective eruptions. These data were accessed 9 February 2012; as of that date, the latest eruption reported by AVO was the one of 19 July 2011. From the AVO web site.

    Item    Eruption dates (start-stop;    BGVN issue(s)
              ? = questionable event)
            
    a.      2 Feb-15 Apr 2001              26:01, 26:04
    b.      27 Apr-27 Sep 2005             30:09
    c.      6 Feb-6 Feb 2006               31:01, 31:06
    d.      23 May-23 May 2006             31:06, 31:07
    e.      24 Aug-28 Oct 2006             31:09
    f.      Jun 2007-28 Oct 2008           33:02, 33:07
    g.      2 Jan-21 Jan 2009              33:11
    h.      26 Jun-26 Jun 2009             34:10
    i.      2 Oct-2 Oct 2009               34:10
    j.      30 May-2 Jun 2010              35:06
    k.      12 Sep-12 Sep 2010 (?)         36:05
    l.      19 Jul 2011 ± 7 days           36:08

We amend some of our previous Bulletin reports with the following excerpts from USGS reports of Cleveland eruptions since 2001, ending with the last Bulletin containing a report on Cleveland (BGVN 36:08). The dates for the eruptions are the start and stop dates from the USGS reports.

Item a, Table 4 - BGVN 26:01: On 19 February 2001, Cleveland volcano erupted explosively at ~1430 UTC and AVO established the eruption termination date as 15 April 2001. However, after the eruption, AVO received reports indicating that precursory emission activity had taken place. Most graphic was a photograph taken on 2 February 2001 by a pilot flying by the volcano showing a dark, lobate deposit on the snow-covered SW flank and robust steaming from the summit crater.

Item a, Table 4 - BGVN 26:04: According to AVO, in 2001, ash fall from the February 2001 eruption of Cleveland was observed only at Nikolski over a ~5 hr on 19 February 2001. A sample from Nikolski showed that the ash was composed of glass shards, crystals, and lithics. The glass was dacitic and had a magmatic morphology rather than phreatomagmatic.

Item b, Table 4 - BGVN 30:09: On 27 April 2005, the Federal Aviation Association (FAA) alerted AVO of a pilot report of eruptive activity (ash cloud 4.6-5.5 km altitude) in the vicinity of Cleveland (based on coordinates from the pilots). Although satellite images and nearby seismic stations showed no evidence of activity, a one-time Urgent Pilot Report and a one-time SIGMET were issued.

Item c, Table 4 - BGVN 31:01: AVO noted that by the end of 6 January 2006 there were no further reports or images of ash production at Cleveland.

Item f, Table 4 - BGVN 33:02: Satellite data from February 2007 revealed evidence of recent activity involving ejection of bombs and debris on the upper flanks and generation of water-rich flows that traveled halfway to the coast. No ash emissions or ash fall deposits were observed. This level of activity -accompanied by persistent thermal anomalies - occurred throughout the spring and early summer. On 4 March 2008, a pilot reported minor ash to 1.5 km above sea level in the vicinity of Cleveland, and a weak thermal anomaly was observed the following day.

Item g, Table 4 - BGVN 33:11: The volcano was relatively quiet until 28 October 2008, when an ash cloud rising to ~4.6 km and drifting E was spotted in satellite imagery. On 29 October, another cloud, 160 km long and drifting NE at an altitude of 3.0 km with little or no ash was observed. A strong thermal anomaly over the summit of the volcano was noted on 30 October 2008, but given the low-level nature of the recent activity, AVO did not elevate the Color Code or Alert Level.

Item k, Table 4 - BGVN 36:05: AVO continued to detect thermal anomalies on 14, 15, 25, and 26 September 2010, and 1 October. During the other days, clouds prevented satellite observation of Cleveland. Although the weather usually prevented observations of Cleveland, weak thermal anomalies were also detected on 14, 19, 25, and 29 October 2010. Clouds completely obscured observations for the week of 1-6 November 2010, but thermal anomalies were again detected on 7 November. The weather then remained cloudy until 16,17, 25, 28, and 30 November 2010, when thermal anomalies were again visible. Thermal anomalies were also recorded on 6, 13, 14, 23, and 27 December 2010, and weak thermal anomalies were visible on 1, 11, and 16 January 2011. A weak thermal anomaly was observed on 1 February 2011, and on 9 February a pilot overflew Cleveland and reported minor, repetitive steam emissions rising hundreds of meters above the summit. The snow on the flanks was pristine, with no indication of recent ash emissions. Steam emissions are common at Cleveland and do not indicate an increased level of unrest.

References. Cervelli, P. F., and Cameron, C. E., 2008, Causation or coincidence? The correlations in time and space of the 2008 eruptions of Cleveland, Kasatochi, and Okmok Volcanoes, Alaska, EOS, Transactions of the American Geophysical Union, Fall Meeting 2008, abstract ##A53B-0278.

Diefenbach, A.K., Guffanti, M., and Ewert, J.W., 2009, Chronology and References of Volcanic Eruptions and Selected Unrest in the United States, 1980-2008, U.S. Geological Survey Open-File Report 2009-1118, 85 p (http://pubs.usgs.gov/of/2009/1118/).

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; USAToday (URL: http://www.usatoday.com).

10/2013 (BGVN 38:10) Dome growth and destruction during 2012-2013

In the previous Bulletin report (BGVN 37:01) we discussed a cycle of lava-dome growth within the summit crater from late 2011 through early 2012. That cycle of extrusion and destruction of domes continued into 2013. The lava dome observed on 30 January 2013 persisted to the end of this reporting period, September 2013. The dynamic conditions at Cleveland caused the Alaska Volcano Observatory (AVO) to report numerous changes in the Aviation Color Code and Alert Level, fluctuating between Yellow/Advisory and Orange/Watch throughout this time period (table 5).

Table 5.During 2012-2013, AVO announced changes in the Aviation Color Code and Volcano Alert Level for Cleveland. AVO and other US Observatories use a combination color code and alert level system that addresses both airborne and ground-based hazards (Gardner and Guffanti, 2006); the lowest level in this 4-step system is Normal/Green and the highest is Warning/Red. Courtesy of USGS-AVO.

Aviation Color Code/ Volcano Alert Level Date of Change
Orange/Watch 31 Jan. 2012
Yellow/Advisory 23 Mar. 2012
Orange/Watch 28 Mar. 2012
Yellow/Advisory 30 May 2012
Orange/Watch 19 Jun. 2012
Yellow/Advisory 5 Sept. 2012
Orange/Watch 10 Nov. 2012
Yellow/Advisory 21 Nov. 2012
Orange/Watch 6 Feb. 2013
Yellow/Advisory 8 Mar. 2013
Orange/Watch 4 May 2013
Yellow/Advisory 4 Jun. 2013

Continued explosions during 2012-2013. Cleveland has a history of frequent, minor ash emissions particularly during 2005-2009 (McGimsey and others, 2007; Neal and others, 2011) and with more frequency during 2011-2013 (Guffanti and Miller, 2013; De Angelis and others, 2012). During 2012-2013, Cleveland remained unmonitored by ground-based seismic instrumentation; volcanic unrest was primarily detected by the seismic network located on nearby Umnak Island (figure 12). Observations were also conducted with satellites that have capabilities of distinguishing ash from meteorological clouds during clear conditions: GOES (Geostationary Operational Environmental Satellite), POES (Polar Operational Environmental Satellite which carries the AVHRR scanner), and the Terra and Aqua satellites that carry MODIS sensors.

Figure 12. Locations of Cleveland volcano (red triangle) and the infrasound stations in Alaska. Black dots are individual infrasound sensors co-located with seismic monitoring stations, yellow dots are infrasound arrays. The inset shows Umnak Island where the Okmok volcano stations are located; this is the closest seismic network to Cleveland. Map modified from De Angelis and others, 2012.

Additional assessments of explosive activity in this period were aided by (1) direct observations from mariners or pilots (PIREPS); (2) near real-time recordings of ground-coupled airwaves that characteristically arrive at seismic stations as extremely slow velocity signals, ~1 order of magnitude smaller than typical seismic velocity in the crust (De Angelis and others, 2012); (3) new infrasound detection capabilities recently expanded to include a station on Akutan (~500 km ENE of Cleveland).

De Angelis and others (2012) determined that 20 explosions were detected between December 2011 and August 2012, particularly by infrasound sensors as far away as 1,827 km from the active vent, as well as ground-coupled acoustic waves recorded at seismic stations across the Aleutian Arc. By retrospectively examining the record of airwaves from Cleveland, those authors determined that many explosions had gone unnoticed in satellite images, likely because of poor weather conditions that obscured the signal or because these explosions were brief, small, and lofted little ash.

Significant ash explosions in April-June 2012 and May 2013. During the 2012-2013reporting period , explosions from Cleveland's summit crater were most frequently detected during April and June 2012 (figure 13). Additional explosions were reported by AVO through July 2013. Relative quiescence (which included minor thermal anomalies visible in satellite images) followed and continued through September 2013.

Figure 13. Satellite image of Cleveland collected on 9 June 2012 by the satellite Worldview-2. Snow persisted on the flanks during this time, but recent, minor ash deposits were visible around the summit crater. In this view, N is at the top of the image and the narrow isthmus connecting Cleveland to the rest of Chuginadak Island is at the R-hand side of the image (although not visible here). Courtesy of USGS-AVO and Digital Globe.

During 2012-2013, at least two explosions were large enough to generate ash plumes that reached >4 km above the summit crater. Both were reported by the Anchorage Volcanic Ash Advisory Center (VAAC) on 7 April 2012 and 4 May 2013. The April event produced a plume that rose ~6 km a.s.l.; AVO reported that ash drifted E at 18 m/s. The 4 May 2013 event (figure 14) generated an ash plume that rose ~4.6 km a.s.l. Based on POES data and AVO observations, the ash drifted SE at ~10 m/s and dissipated within 5 hours.

Figure 14. (A) AVHRR satellite image of Cleveland was taken at 0643 on 4 May 2013. This infrared image shows elevated temperatures that were present at Cleveland's summit and a small, low-level eruption plume containing minor amounts of ash trailed to the E. The thermal anomaly appears as a white dot in the center of the image. Courtesy of USGS-AVO/UAF-GI. (B) True-color Terra MODIS satellite image acquired at 2050 on 4 May 2013 shows an eruption plume from Cleveland. The diffuse ash plume extended from Cleveland's summit and across the SW point of Umnak Island. Courtesy of USGS-AVO and Land Atmosphere Near-real time Capability for EOS (LANCE) system operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS).

During 2012-2013, AVO reported that explosions were frequently attributed to dome destruction. Those events often completely removed the new lava domes from the crater (table 6).

Table 6.Cleveland's lava dome history during 2012-2013 based on a variety of observations of the Cleveland summit crater. Note that an earlier dome was destroyed during 25-29 December 2011 and was confirmed absent by 24 January 2012. Courtesy of USGS-AVO.

New Dome Date Observations
30 January 2012  •40 m across
 •Dome was gone by 11 March 2012
26 March 2012 •70 m across
 •Dome was gone by 4 April 2012
25 April 2012 •25 m across
 •Dome was gone some time before 29 April 2012
3 May 2012 •25 m wide
 •Dome was gone by 6 May 2012
30 January 2013 •100 m wide
•Dome persisted through September 2013

More on elevated surface temperatures during 2012-2013. In addition to the case shown in figure 14A, thermal anomalies in the vicinity of Cleveland's summit crater were frequently detected during this reporting period. AVO inferred that these observations reflected a variety of volcanic activity such as fresh, hot tephra from recent explosions, the hot open conduit at the bottom of the summit crater, incandescent rock such as the above mentioned domes (table 6) at the surface, or hot volcaniclastic flow deposits on the flanks (figure 15).

Figure 15. Composite image of the Cleveland summit area compiled from Landsat-8 images acquired on 8 June 2013. N is at the top of the image. Thermal infrared data are overlain onto a visible wavelength image; the extent of lava flows erupted during early May 2013 appears bright with colors corresponding to temperatures in the key (upper-L-hand corner). Temperature values are given in Kelvin, and range from 303-312 K (86-102 °F). The longest lava flows extended to ~715 m downslope from the summit. The summit was also covered by dark ash deposits and is surrounded by a low cloud deck. Courtesy of USGS-AVO.

AVO reported that a satellite-based thermal alarm was triggered on 12 June 2012, attributed to the formation of hot lahars or rubble flows on Cleveland's flanks. While no lava dome was present at that time (see table 6), this was a significant event that transported debris to 700 m a.s.l. on the NW flank (note that Cleveland has a summit elevation of 1,730 m). Other deposits, likely from other lahars, were mobilized on the NNW and NNE flanks. The deposits were mainly confined to drainages; deposits extended >1.5 km in length. Flowage features on the SE and SW flanks reached >1 km in length. AVO scientists also noted that all flanks had shown signs of melted snow but cautioned that the visual effect could also be attributed to non-eruptive remobilization of existing fragmental material on the steep flanks.

Volcaniclastic deposits were also noted based in satellite images on 10 November 2012. These features were located on the E flank and extended ~1 km down the slope.

References: De Angelis, S., Fee, D., Haney, M., and Schneider, D., 2012. Detecting hidden volcanic explosions from Mt. Cleveland Volcano, Alaska with infrasound and ground-coupled airwaves, Geophysical Research Letters, 39, L21312, doi:10.1029/2012GL053635.

Gardner, C.A. and Guffanti, M.C., 2006. U.S. Geological Survey's Alert Notification System for Volcanic Activity, USGS Fact Sheet 2006-3139.

Guffanti, M., and Miller, T., 2013. A volcanic activity alert-level system for aviation: review of its development and application in Alaska: Natural Hazards, 15 p., doi:0.1007/s11069-013-0761-4.

McGimsey, R.G., Neal, C.A., Dixon, J.P., and Ushakov, Sergey, 2007. 2005 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2007-5269, 94 p., available at http://pubs.usgs.gov/sir/2007/5269/.

Neal, C.A., McGimsey, R.G., Dixon, J.P., Cameron, C.E., Nuzhaev, A.A., and Chibisova, Marina, 2011. 2008 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2010-5243, 94 p., available at http://pubs.usgs.gov/sir/2010/5243.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA (URL: http://www.gi.alaska.edu/ ), and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.dggs.alaska.gov/); and Anchorage Volcanic Ash Advisory Center (VAAC), 6930 Sand Lake Road, Anchorage, AK 99502, USA (URL: http://vaac.arh.noaa.gov/list_vaas.php).

Beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited, dumbbell-shaped Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Cleveland is joined to the rest of Chuginadak Island by a low isthmus. The 1730-m-high Mount Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name for Mount Cleveland, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2013 Dec 28 2014 Jun 5 Confirmed 2 Historical Observations
2011 Jul 20 2013 May 13 Confirmed 2 Historical Observations Summit crater
[ 2010 Sep 12 ± 1 days ] [ 2010 Sep 26 ] Uncertain 2  
2010 May 30 2010 Jun 2 (?) Confirmed 2 Historical Observations
2009 Oct 2 2009 Dec 12 (?) Confirmed 2 Historical Observations
2009 Jun 25 2009 Jun 25 Confirmed 2 Historical Observations
2009 Jan 2 2009 Jan 21 Confirmed 2 Historical Observations
2007 Jun 17 (?) 2008 Aug 12 (?) Confirmed 2 Historical Observations
2006 Feb 6 2006 Oct 28 Confirmed 3 Historical Observations
2005 Mar 13 (?) 2005 Nov 27 ± 1 days Confirmed 2 Historical Observations
2001 Feb 2 (in or before) 2001 Apr 15 (?) Confirmed 3 Historical Observations
1997 May 5 1997 May 5 Confirmed 2 Historical Observations
1994 Oct 20 1994 Oct 20 Confirmed 1 Historical Observations
1994 May 25 1994 May 25 Confirmed 3 Historical Observations
[ 1989 Oct 25 ± 3 days ] [ Unknown ] Uncertain 0  
1987 Jun 19 1987 Aug 28 Confirmed 3 Historical Observations
1986 Apr 28 1986 May 27 (in or after) Confirmed 2 Historical Observations
[ 1985 Dec 10 ] [ Unknown ] Uncertain 1  
1984 Jul 12 1984 Jul 12 Confirmed 1 Historical Observations
[ 1975 Sep ] [ Unknown ] Uncertain    
[ 1953 Jun 25 ] [ Unknown ] Uncertain    
[ 1951 Nov 1 ] [ 1951 Dec ] Uncertain    
1944 Jun 10 1944 Jun 12 Confirmed 3 Historical Observations
1938 Unknown Confirmed   Historical Observations
1932 Jan 1 Unknown Confirmed   Historical Observations
[ 1929 Mar ] [ Unknown ] Uncertain    
1897 Unknown Confirmed   Historical Observations
1893 Unknown Confirmed   Historical Observations

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

Chuginadak
Herbert Island, capped by the snow-covered peak in the right foreground, is a classic, symmetrical stratovolcano with a 2-km-wide summit caldera that is breached to NW. No historical eruptions have been recorded from 1280-m-high Herbert volcano, which, like many other Aleutian volcanoes, has not been studied geologically. This June 23, 1987, view from the WSW shows a steam plume originating from conical Cleveland volcano in background, whose slopes are darkened by ashfall from an eruption that began on June 19.

Photo by Harold Wilson (Peninsula Airways), 1987 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys).
An eruption in 1987 began with explosive activity on June 19 that deposited ash over fresh snow on all sides of the volcano. On June 23, the date of this photo, a lava flow from the summit was observed that eventually extended 2.5 km down the ESE flank. Lava fountaining was observed on July 22, and on August 28 a large explosive eruption produced an eruption column that reached over 10 km altitude.

Photo by Harold Wilson (Peninsula Airways), 1987, courtesy of John Reeder (Alaska Div. Geology & Geophysical Surveys).
An aerial view of the upper east flank taken at ~1100 local time on June 24, 1987, show a lava flow traveling down the ESE flank. Incandescent lava can be seen at several locations along the flow, which eventually traveled 2.5 km from the summit. The snow-covered slopes of the volcano area darkened by ashfall from an eruption that began on June 19.

Photo by Harold Wilson, 1987 (Peninsula Airways), courtesy of John Reeder (Alaska Div. Geology Geophysical Surveys).
A steam plume rises above the summit crater of Cleveland volcano on June 23, 1987. The upper flanks of the volcano are darkened by ashfall from an explosive eruption that began on June 19. The steaming summit vent began producing a lava flow on June 23 that eventually descended 2.5 km down the ESE flank. Lava fountaining was observed on July 22. A large explosive eruption took place on August 28, the last day of the eruption. This view from the ENE show part of Herbert volcano behind the plume at the left.

Photo by Harold Wilson, 1987 (Peninsula Airways), courtesy of John Reeder (Alaska Div. Geology Geophysical Surveys).
An aerial view of two symmetrical Aleutian volcanoes shows the effect of volcanic ashfall. Both Cleveland (left) and Carlisle (right) volcanoes are snow-covered, but the flanks of Cleveland volcano in this June 24, 1987, view from the ESE are darkened by deposits of ash from an explosive eruption that began on June 19.

Photo by Harold Wilson, 1987 (Peninsula Airways), courtesy of John Reeder (Alaska Div. Geology Geophysical Surveys).
The beautifully symmetrical Mount Cleveland forms the western half of Chuginadak Island. The 1730-m stratovolcano is one of the most active volcanoes of the Aleutian Islands. This July 24, 1994, view from the west shows the summit region darkened by ashfall that may have originated from an eruption reported on May 25. Dark lava flows from earlier eruptions can be seen on the flanks of the volcano.

Photo by Michelle Harbin, 1994 (courtesy of Alaska Volcano Observatory, U.S. Geological Survey).

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.

Coats R R, 1950. Volcanic activity in the Aleutian Arc. U S Geol Surv Bull, 974-B: 35-47.

Dean K G, Dehn J, Papp K R, Smith S, Izbekov P, Peterson R, Kearney C, Steffke A, 2004. Integrated satellite observations of the 2001 eruption of Mt. Cleveland, Alaska. J Volc Geotherm Res, 135: 51-73.

Henning R A, Rosenthal C H, Olds B, Reading E (eds), 1976. Alaska's volcanoes, northern link in the ring of fire. Alaska Geog, 4: 1-88.

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

Miller T P, McGimsey R G, Richter D H, Riehle J R, Nye C J, Yount M E, Dumoulin J A, 1998. Catalogue of the historically active volcanoes of Alaska. U S Geol Surv Open-File Rpt, 98-582: 1-104.

Motyka R J, Liss S A, Nye C J, Moorman M A, 1993. Geothermal resources of the Aleutian arc. Alaska Div Geol Geophys Surv, Prof Rpt, no 114, 17 p and 4 map sheets.

Smith R L, Shaw H R, Luedke R G, Russell S L, 1978. Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States. U S Geol Surv Open-File Rpt, 78-925: 1-25.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

Volcano Types

Stratovolcano

Tectonic Setting

Subduction zone
Intermediate crust (15-25 km)

Rock Types

Major
Andesite / Basaltic Andesite
Dacite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
0
9

Affiliated Databases

Large Eruptions of Cleveland 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.