Most Recent Weekly Report: 28 August-3 September 2024 Cite this Report

AVO reported that volcanic unrest at Shishaldin declined over the past several months. Slightly elevated seismicity, small infrasound signals, and weak gas emissions persisted, but there were no signs of explosivity nor the presence of lava in the summit crater. AVO noted that the activity was at background levels, and at 0900 on 30 August the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale) and the Aviation Color Code was lowered to Green (the lowest color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Most Recent Bulletin Report: June 2020 (BGVN 45:06) Cite this Report

Weekly Reports - Index

2024: February | August
2023: July | August | September | October | November | December
2021: January | March | October
2020: January | February | March | April | June
2019: July | August | September | October | November | December
2018: February
2017: December
2016: March
2015: January | February | March | April | May | June | July | August | September | October | November
2014: January | February | March | April | May | June | July | August | September | October | November | December
2009: January | February | July | October
2008: February | December
2004: April | May | June | July | September | October
2002: May

28 August-3 September 2024 Cite this Report

AVO reported that volcanic unrest at Shishaldin declined over the past several months. Slightly elevated seismicity, small infrasound signals, and weak gas emissions persisted, but there were no signs of explosivity nor the presence of lava in the summit crater. AVO noted that the activity was at background levels, and at 0900 on 30 August the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale) and the Aviation Color Code was lowered to Green (the lowest color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 February-20 February 2024 Cite this Report

AVO reported that low-level unrest at Shishaldin continued during 13-20 February. Occasional small volcanic earthquakes were recorded daily by the seismic network. Robust steaming was observed in satellite and webcam images and reported by local pilots on 13 February, and minor steaming was visible in satellite and webcam images during 14-15 February. AVO noted that steam emissions were not uncommon at Shishaldin. At 1126 on 17 February AVO lowered the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code to Yellow (the second lowest color on a four-color scale) noting that there were no signs of eruptive activity.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 February-13 February 2024 Cite this Report

AVO raised the Volcano Alert Level for Shishaldin to Watch (the third level on a four-level scale) and the Aviation Color Code to Orange (the third color on a four-color scale) at 1246 on 11 February due to a slight increase in volcanic activity. Minor ash emissions were observed in a webcam image timestamped at 0925 on 11 February. The low-level ash cloud extended from the summit crater and draped over the N flank. AVO posited that since seismic signals typically associated with surficial mass flows were recorded at the same time as the ash emission event, a collapse event of previously deposited material on the upper area of the cone could have occurred. After the minor ash episode occurred, weather clouds obscured views of the summit and there was no evidence of ash in satellite images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

27 December-2 January 2024 Cite this Report

On 2 January AVO lowered the Volcano Alert Level for Shishaldin to Advisory (the second level on a four-level scale) and the Aviation Color Code to Yellow (the second color on a four-color scale), noting that activity had declined over the past two months since the last significant explosive event on 3 November. Small explosions continued to be periodically detected in infrasound data, though no new deposits inside or outside the crater had recently been observed. Surface temperatures detected in satellite data were low, suggesting that no fresh lava was present in the summit crater. Steaming from the crater continued to be observed in webcam images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 December-26 December 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 20-26 December. Seismicity was slightly elevated and consisted of small low-frequency earthquakes and tremor. Minor steaming was visible in a webcam image during 20-21 December. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 December-19 December 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 12-19 December. Seismicity remained low and was characterized by small low-frequency earthquakes recorded daily and tremor recorded during 15-19 December. Barely elevated surface temperatures identified in satellite images during 13-14 December were likely associated with cooling deposits on the upper flanks. Minor steaming at the summit was visible in webcam images on 15 December. Infrasound signals indicating weak explosions were detected during 17-18 December but did not produce ash emissions; only minor steaming at the summit was visible in clear webcam images. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 December-12 December 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 6-12 December. Seismicity remained low with small, frequent, low-frequency earthquakes recorded daily. Weak explosions were detected in infrasound data during 6 and 8-9 December, though none produced ash. Elevated surface temperatures were identified in a clear satellite image during 8-9 December, and minor steaming at the summit was observed in webcam images during 8-10 December. Cloudy weather sometimes prevented views of the summit. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 November-5 December 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 29 November-5 December. Seismicity remained elevated, with frequent small low-frequency earthquakes. Weak explosions were identified in infrasound data during 29 November-3 December. Activity observed at the summit and upper NE flank collapse scarp consisted of weakly elevated surface temperatures detected in satellite images and gas-and-steam plumes seen in webcam images. Persistent degassing activity was observed during 29 November-3 December. Weak degassing activity produced steam plumes that drifted S of Unimak Island during 4-5 December. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 November-28 November 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 22-28 November. Seismicity began to decrease on 21 November, though remained elevated with ongoing seismic tremor and small, low-frequency earthquakes recorded during the week. Elevated surface temperatures were identified in satellite images during 22 and 25-26 November. Robust steam emissions rising from the summit vent as well as from a scarp on the upper NE flank, near the summit were visible in satellite and webcam images drifting 50 km SSE during 25-26 November. During 27-28 November steam plumes were visible in webcam images and small explosions were observed in seismic and local infrasound data. Weather clouds often prevented views of the volcano. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 November-21 November 2023 Cite this Report

AVO reported that unrest continued at Shishaldin during 15-21 November. Seismicity remained elevated with ongoing seismic tremor and small, low-frequency earthquakes. Elevated surface temperatures were identified in satellite images during 15-16 and 19-20 November. Robust steam emissions were visible in satellite and webcam images during 17-20 November. Small explosions were observed in infrasound data during 18-21 November, consistent with weak Strombolian activity. Sulfur dioxide emissions were also identified in satellite images. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 November-14 November 2023 Cite this Report

AVO reported that eruptive activity continued at Shishaldin during 8-14 November. Seismicity remained elevated; the seismic network recorded ongoing tremor events and small, low-frequency earthquakes. During 8 November, infrasound sensors detected signals associated with small explosions, and a sulfur dioxide plume was detected by satellite sensors; material ejected during the explosions likely remained confined within the summit crater. Elevated surface temperatures of the summit crater were detected in satellite data during the nights of 11-13 November. Gas-and-steam emissions were occasionally seen in webcam and satellite images; views were obscured by weather clouds most days.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 November-7 November 2023 Cite this Report

AVO reported that the thirteenth significant explosive event since 12 July was recorded at Shishaldin on 2 November. An increase in seismic and infrasound tremor amplitudes began at 1940 on 2 November, indicating a likely eruption. The Volcano Alert Level was raised to Watch (the third level on a four-level scale) and the Aviation Color Code was raised to Orange (the third color on a four-color scale), though ash was not identified in satellite data. At 2000 a sustained ash cloud drifting W was identified in satellite data at an altitude of 6.1 km (20,000 ft) a.s.l. By 0831 on 3 November ash emissions were no longer visible in satellite images and seismic and infrasound data indicated a decline in activity. During 4-7 November seismic activity remained elevated with ongoing tremor and small, low-frequency earthquakes. Minor emissions of steam and sulfur dioxide were visible in webcam and satellite images. Elevated surface temperatures were identified in satellite images on a few occasions. Infrasound signals consistent with small explosions were recorded during 5-7 November.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 October-31 October 2023 Cite this Report

AVO reported that unrest at Shishaldin continued during 25-31 October with observations suggesting ongoing degassing of magma at shallow levels beneath the summit. Seismicity was elevated, consisting of seismic tremor and small, low-frequency earthquakes, though activity had begun to slowly decline after the last explosive event on 3 October. Minor steam emissions were visible in webcam images during 24-25 October. Elevated surface temperatures were identified in satellite data during 28-29 October, though they did not indicate lava at the surface. On 31 October the Volcano Alert Level was lowered to Advisory (the second level on a four-level scale) and the Aviation Color Code was lowered to Yellow (the second color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 October-24 October 2023 Cite this Report

AVO reported that activity at Shishaldin through 24 October had remained elevated since the last explosive event which occurred on 3 October. Sulfur dioxide emissions were elevated with daily averages of more than 1,000 tons per day based on satellite data; during periods in between previous explosive events, sulfur dioxide emissions were either low or were not detected. Abundant amounts of steam rose from the summit as well as from a liner feature that extended about 400 m from the summit down the NE flank. Seismicity remained elevated and was characterized by nearly constant seismic tremor and frequent, small, long-period, or low-frequency earthquakes. The seismicity was indicative of the movement of volcanic fluids and gases within the volcano and had been typically low in between previous explosive events. Daily elevated surface temperatures were identified in satellite data, though temperatures were inconsistent with lava at the surface. Pilots reported a prominent steam plume drifting 40 km WSW at altitudes of 3-4.6 km (10,000-15,000 ft) a.s.l. during the afternoon of 21 October. Minor steam emissions were visible in webcam images during 22-24 October. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 October-17 October 2023 Cite this Report

AVO reported that activity at Shishaldin during 10-17 October was characterized by daily sulfur dioxide gas emissions (except on 12 October) and frequent small earthquakes. Daily elevated surface temperatures were identified in satellite images. Steam-and-gas plumes observed in webcam images were reported each day, though weather conditions occasionally prevented views. The emissions were robust during 14-16 October, likely generated by the interaction of hot material and snow and ice. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 October-10 October 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 4-10 October. After the significant explosive event on 3 October, ash plumes continued to be produced for over eight hours until around 1400. Hot rock avalanches had descended the SW and NE flanks; two explosion craters located at the base of the NE deposits, about 3.2 km from the crater rim, were the sources of persistent ash. During 3-4 October small, local ash plumes from occasional collapse events were visible in webcam images. Seismicity remained elevated during 4-10 October with small frequent earthquakes. Gas emissions were occasionally visible, though weather clouds occasionally prevented views. Elevated surface temperatures were identified in satellite images during 8-10 October. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

27 September-3 October 2023 Cite this Report

AVO reported that the significant explosive eruption at Shishaldin that occurred on 25 September was the eleventh that had occurred since 14 July, and among the most impactful. Ashfall was reported in several communities downwind and flight cancellations occurred in the region. A large ash cloud quickly rose to 14 km (45,000 ft) a.s.l., produced at least 150 lightning strokes with thunder heard in False Pass, and drifted E along the Alaska Peninsula. Seismicity decreased notably near the end of the strong activity on 25 September and continued to decrease during 26 September-3 October. Satellite data from 26 September showed that significant collapses had occurred at the summit crater and hot, steaming, deposits from pyroclastic flows and lahars were present on all flanks, particularly to the ENE and WSW. A small ash cloud was visible in webcam images on 27 September, likely from a collapse at the summit cone. Elevated surface temperatures were intense during 27-28 September. Minor steaming at the summit crater and from an area on the upper flanks was visible in webcam images on 28 September. Weakly elevated surface temperatures were identified in satellite data during 30 September-1 October and a pilot reported steaming from the vent on 1 October.

Seismicity significantly increased starting at around 2100 on 2 October and around the same time satellite images showed an increase in surface temperature consistent with lava fountaining. Small hot avalanches of rock and lava descended the flank. A distinct increase in infrasound, seismicity, and lighting detections was followed by the identification of an ash plume at 12 km (40,000 ft) a.s.l. at 0520 on 3 October in satellite images. The Aviation Color Code was raised to Red (the highest color on a four-color scale) and the Volcano Alert Level was raised to Warning (the highest level on a four-level scale). By 0931 ash plumes were only rising to altitudes of 6.1-7.6 km (20,000-25,000 ft) a.s.l. and both seismicity and infrasound levels had decreased. At 1036 the Aviation Color Code was lowered to Orange and the Volcano Alert Level was lowered to Watch; seismic and infrasound activity were slightly above background levels and steaming at the summit was observed in webcam images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 September-26 September 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 20-26 September with activity increasing during the week and culminating in a notable eruption during 24-25 September. Seismicity remained elevated during 19-22 September, with tremor and small earthquakes detected by the seismic network. Elevated surface temperatures were identified in satellite images. Minor steaming and small volcanic debris flows on the upper flanks were visible in webcam images on 20 September, a small ash deposit on the upper flank was visible in images the next day.

Seismic tremor increased significantly during 22-23 September. Regional infrasound sensors suggested that low-level eruptive activity was likely occurring within the summit crater by around 1800 on 23 September. Even though seismicity was at high levels, strongly elevated surface temperatures indicating lava at the surface were absent and no ash emissions were detected, though weather clouds at 0.6-4.6 km a.s.l. obscured views. At 0025 on 24 September AVO noted that seismicity was continuing at high levels and nearly continuous small infrasound signals had begun to be detected, likely from low-level eruptive activity. Strongly elevated surface temperatures were identified in satellite images at least by 0900 and persisted throughout the day; the higher temperatures along with infrasound and seismic data were consistent with lava erupting at the summit. Highly elevated surface temperatures detected at around 1700 suggested the start of more vigorous lava fountaining. Beginning at around 1800 low-level ash emissions rose to altitudes less than 4.6 km (15,000 ft) a.s.l. and quickly dissipated. At around midnight seismic data indicated that lava flows were active on the N flank, and lava fountaining over the crater rim was visible during early morning hours on 25 September. At 0540 a significant ash plume began to rise from the summit prompting AVO to raise the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale). The ash cloud produced lightning, quickly rose to 14 km (45,000 ft) a.s.l., and drifted E along the Alaska Peninsula. Seismicity dropped rapidly to near-background levels at around 0600. The ash plume detached from the summit at around 0700 and drifted ESE at an altitude of 11.6 km (38,000 ft) a.s.l. Ash emissions continued until about 0820, rising to 6.1-7.6 km (20,000-25,000 ft) a.s.l. Small explosions at the vent area continued to be detected in infrasound data. At noon the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. Trace to minor amounts of ashfall were reported by the communities of False Pass, King Cove, Cold Bay, and Sand Point.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 September-19 September 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 13-19 September. Eruptive activity increased during 13-14 September. Elevated surface temperatures began to be identified in satellite images during the afternoon of 13 September and they increased later that night. Seismic tremor amplitudes began to increase at around 1800 and small explosions were detected in seismic and infrasound data. Incandescent lava at the summit was seen in a webcam image at 0134 on 14 September during a period of elevated tremor. No ash emissions were visible though high weather clouds may have obscured them.

Seismic tremor began to increase sometime around 0900 on 15 September and rapidly intensified. An explosive eruption began at around 1710, prompting AVO to the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale). Within about 30 minutes ash plumes drifted E below a weather cloud deck at 8.2 km (27,000 ft) a.s.l., unseen in satellite views. The National Weather Service estimated that an ash-rich plume rose as high as 12.8 km (42,000 ft) a.s.l. and produced volcanic lightning. The upper parts of the plume detached by 1830, at about the same time that seismicity dramatically decreased. Lightning was again detected beginning around 1930, suggesting that ash emissions continued. Ongoing explosions were detected in infrasound data, at a lower level than during the most energetic phase of this event. Trace amounts of ash fell in False Pass (38 km ENE) during 1800-2030. Lightning was last detected at 2048. By 2124 the intensity of the eruption had decreased, and ash emissions were likely rising to altitudes less than 6.7 km (22,000 ft) a.s.l. Seismicity returned to pre-eruption levels; at 1244 on 16 September AVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange. A plume of sulfur dioxide emitted during 14-15 September was detected over the North Pacific. Seismicity remained elevated with tremor and small daily earthquakes occurring over 16-18 September. Elevated surface temperatures at the summit were identified in satellite data and minor steam emissions were visible in webcam views.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 September-12 September 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 6-12 September. Seismicity remains elevated and characterized by weak but steady tremor, small low-frequency earthquakes, and small explosions; explosions were not reported on 12 September. Elevated surface temperatures were identified daily in satellite images and were sometimes intense. A Significant Meteorological Information (SIGMET) notice issued on 6 September advised aircraft of a low-level ash plume drifting SSE at 1.5-1.8 km (5,000-6,000 ft) a.s.l. Small plumes visible in webcam images drifted ESE and SSE during 6-7 September. Additional small diffuse steam-and-gas plumes from the summit were observed in web camera images during 9-11 September. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

30 August-5 September 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 30 August-5 September. Weather conditions sometimes prevented observations. Daily, small, repetitive explosions were recorded in seismic and infrasound data, though high winds occasionally masked the signals. Elevated surface temperatures at the summit were identified in satellite data on most days. Hot deposits on the NE flank, emplaced during 25-26 August, were visible in a 1 September satellite image, along with steam emissions obscuring the summit vent. Possible incandescence at the summit was visible in nighttime webcam images during 3-4 September, and small steam emissions were visible in daytime images.

Seismicity began to gradually increase at around 0300 on 5 September and activity escalated around 0830. A pilot in the vicinity of the volcano reported an ash plume at about 7.6 km (25,000 ft) a.s.l. at 0842 that was continuing to rise. The ash plume was large and may have risen as high as 9.7 km (32,000 ft) a.s.l. and drifted SSE based on satellite images. AVO raised the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale) at 0901. Seismic amplitude decreased rapidly at around 1100, and remained low, and the altitude of ash emissions observed in satellite images also decreased to an estimated 4.5 km (15,000 ft) a.s.l. By 1200 the lower-altitude portion of the ash plume had drifted 125 km E. Significant ash emissions ended by 1330 based on webcam images. At 1440 AVO lowered the Aviation Color Code to Orange and the Volcano Alert Level to Watch. This event marks the ninth period of elevated eruptive activity resulting in significant ash emissions and mass flows of volcanic debris on the volcano's flanks since the onset of the current eruption.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 August-29 August 2023 Cite this Report

AVO reported that the eruption at Shishaldin continued during 23-29 August. Low-level explosive activity likely continued during 23-24 August based on seismic and infrasound data. Elevated surface temperatures at the summit were identified in satellite data; webcam images were obscured by weather clouds. Seismic tremor began increasing at around 0300 on 25 August and was followed by elevated surface temperatures identified in satellite images, consistent with lava erupting at the summit. Small explosions were recorded in infrasound data. At 1204 AVO raised the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale) in response to a pilot report of an ash plume at 8.5 km (28,000 ft) a.s.l. Seismicity peaked at 1630 and then began to rapidly decline at around 1730. Ash plumes rose as high as 10 km (32,000 ft) a.s.l. and drifted as far as 400 km NE. Ash plume altitudes began to decrease and by 2020 the plumes were rising as high 6.4 km (21,000 ft) a.s.l. and drifting NE. Ash emissions ended at 0000 on 26 August and seismicity was at low levels; AVO lowered the Aviation Color Code to Orange and the Volcano Alert Level to Watch. This large, ash-producing explosive event was the eighth to occur since the eruption started. Minor explosive activity within the summit crater was detected during 26-28 August and strongly elevated surface temperatures visible in satellite imagery. On 26 August a gas plume drifted NE. An AVO field crew working on Unimak Island observed a mass flow that descended the upper flanks beginning around 1720 on 27 August. The flow produced a short-lived ash cloud that rose to around 4.5 km (15,000 ft) a.s.l. and rapidly dissipated. The mass flow was likely caused by the collapse of lava spatter that had accumulated on the summit crater rim.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

16 August-22 August 2023 Cite this Report

AVO reported that a vigorous eruption at Shishaldin on 15 August produced ash plumes that rose 9.1-11 km (30,000-36,000 ft) a.s.l. and drifted 100 km NE. Seismicity declined by 1322. An associated sulfur dioxide cloud that drifted over parts of Alaska and western Canada had mostly dissipated by 16 August, though remnants continued to be identified in satellite images at least through 18 August.

Seismicity was low during 16-22 August. Elevated surface temperatures observed daily in satellite images indicated hot material on the upper parts of the volcano. Small steam plumes with minor amounts of ash were visible in webcam images during 16-19 August. Small explosions were detected in infrasound data on the morning of 19 August and were consistent with pilot reports of small, short-lived ash plumes rising about 4.3 km (14,000 ft) a.s.l. Low-level explosive activity continued to be recorded during 20-21 August, though weather clouds sometimes prevented views; no emissions were visible in clear webcam images on the morning of 20 August. A billowing white plume was observed by an AVO field crew working nearby on 21 August. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

9 August-15 August 2023 Cite this Report

AVO reported that the effusive and explosive eruption at Shishaldin continued during 9-15 August. Seismicity was generally low during 9-14 August with a few local earthquakes detected on some days; no significant explosive activity was observed in seismic or infrasound data. Elevated surface temperatures were observed in satellite images caused by a small lava flow at the summit. Minor steam-and-gas emissions were visible in webcam or satellite images, though weather clouds sometimes prevented views. At 1827 on 14 August AVO noted that seismic tremor had steadily increased during the afternoon and erupting lava at the summit was evident in a satellite image. Explosion signals began to be detected at 0200 on 15 August. By 0335 satellite images showed an ash cloud drifting NE at 7.6 km (25,000 ft) a.s.l. and lightning was detected in the vicinity of the volcano. The ash cloud drifted 100 km NE over the Bering Sea and may have risen as high as 11 km (36,000 ft) a.s.l. Seismicity was significantly elevated during the eruption but had declined by 1322, though levels continued to indicate ongoing, low-level activity; a pilot reported that ash emissions continued, rising as high as 4.9 km (16,000 ft) a.s.l. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

2 August-8 August 2023 Cite this Report

AVO reported that the effusive and explosive eruption at Shishaldin continued during 1-8 August. Low-level ash emissions rose to below 3 km (10,000 ft) a.s.l. and drifted over 90 km N during 1-2 August. Seismicity was low but punctuated by a few episodes of volcanic tremor associated with the ash emissions. Elevated surface temperatures were consistent with cooling lava over a few days but had begun to increase and were visible though moderate weather cloud cover during 2-3 August; the increasing temperatures were consistent with lava effusion. Seismic tremor began to steadily increase at around 1036 on 3 August. Explosive activity about 20 hours later was detected using infrasound and seismic data. An ash cloud was visible in a satellite image at 0520 on 4 August rising to 7.6 km (25,000 ft) a.s.l. and drifting 60-75 km NE. Pilots saw and reported the plume at 0836. By 0900 the plume had risen to 9 km (30,000 ft) a.s.l., prompting AVO to raise the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale) at 1017. The National Weather Service issued a Significant Meteorological Information (SIGMET) statement for the ash cloud and a Special Weather Statement warned of possible trace amounts of ash on marine waters downwind of Shishaldin. Seismic tremor levels peaked at 1400 and then sharply declined at 1500 to slightly elevated levels; the plume was sustained during the period of high tremor and drifted N and NE. AVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange at 1955. Seismic tremor levels were low. Ash emissions were possibly continuing but they could not be confirmed due to meteorological clouds cover. Elevated surface temperatures observed in satellite data during 5-8 August were consistent with cooling lava. Seismicity has remained low with a few daily local earthquakes.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

26 July-1 August 2023 Cite this Report

AVO reported that the eruption at Shishaldin was continuing during 26 July through 1 August. Seismicity began to increase around 2200 on 25 July, followed by explosion signals detected using infrasound after 0200 on the 26th. A sustained ash cloud was reported at 6 km (15,000 ft) a.s.l. at 0351 on 26 July that drifted ENE, along with an associated sulfur dioxide plume that drifted NE. Diffuse ash emissions were seen in satellite imagery extending about 125 km from the volcano, though weather clouds began to obscure views beginning around 1130. Low-frequency earthquakes and volcanic tremor decreased, and significant explosions were no longer detected in infrasound data, following the activity early on 26 July. Gas-and-steam emissions from the summit crater were observed in webcam images during 29-30 July. Strong-to-moderately elevated surface temperatures continued to be observed in satellite data throughout the week. Satellite images on 1 August showed that some slumping had occurred on the E crater wall. The Volcano Alert Level remained at Watch (the second highest on a four-level scale) and the Aviation Color Code remained at Orange (the second highest on a four-level scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

19 July-25 July 2023 Cite this Report

AVO reported that the effusive and explosive eruption at Shishaldin was continuing during 18-25 July. Satellite images acquired on 18 July, after a period of activity where ash plumes rose to 9.1 km (30,000 ft) a.s.l., showed ash deposits extending to the SW as well as to the SSE where they reached the shore of Unimak Island. Pyroclastic flow deposits up to 3 km long were visible on the N, E, and S flanks, and deposits from lahars triggered by those events extended farther down the flanks. Weather clouds often obscured webcam and satellite views of the summit during 19-21 July, though elevated surface temperatures consistent with low-level eruptive activity in the summit crater were visible in some clear images. Seismicity was low and no infrasound signals indicating explosive activity were detected.

Elevated surface temperatures detected in satellite images overnight during 21-22 July, despite weather cloud cover, were consistent with increased lava effusion. Sulfur dioxide emissions were detected in satellite data midday on 22 July. In a special notice issued at 1653 on 22 July AVO noted that eruptive activity had intensified over the previous six hours, characterized by a steady increase in seismic tremor and intermittent infrasound signals consistent with small explosions. Pilots first reported low-level ash plumes at around 1900. By 2330 the ash plume had risen to 9 km (30,000 ft) a.s.l. based on additional pilot reports and satellite images. The Aviation Color Code was raised to Red (the highest color on a four-color scale) and the Volcano Alert Level was raised to Warning (the highest level on a four-level scale) at 2343. Ash emissions were sustained for just over an hour (from 2320 on 22 July to 0030 on 23 July) and rose as high as 11 km (36,100 ft) a.s.l.; by the end of the period ash plume altitudes had declined to 4.6 km (15,000 ft) a.s.l. Seismic tremor peaked at 0030 on 23 July and then began to rapidly decline at 0109. Activity had significantly declined, and tremor levels were low, by 0418; AVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange. The ash plume had detached and was drifting NE along the Alaska Peninsula. Bursts of increased seismicity were detected by the seismic network throughout the morning but overall remained at low levels. Elevated surface temperatures were identified in satellite images until about 0600. During 23-24 July pilots reported seeing vigorous steam-and-gas plumes rising to about 3 km (10,000 ft) a.s.l.; the plumes may have contained minor amounts of ash. Seismicity was low.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

12 July-18 July 2023 Cite this Report

AVO reported that a new eruption at Shishaldin began after increasing activity. Intermittent tremor and low-frequency earthquakes had gradually become more regular and consistent during 10-11 July, and strongly elevated surface temperatures at the summit were identified in satellite images those same days. The Volcano Alert Level was raised to Advisory (the second level on a four-level scale) and the Aviation Color Code was raised to Yellow (the second color on a four-color scale). Late on 11 July incandescence at the summit was observed in web camera images. Strongly elevated surface temperatures continued to be observed in satellite data and seismic tremor amplitudes increased during 11-12 July; sulfur dioxide emissions were also detected. The observations suggested that lava was likely present at the summit crater, so AVO raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. The US Coast Guard conducted an overflight on 12 July and confirmed that lava was erupting at the summit.

A significant explosion at 0109 on 14 July produced an ash plume that rose 9-12 km (30,000-40,000 ft) a.s.l. and drifted S. Webcam images and photos taken at around 0700 from a ship SW of Unimak Island showed small lahar deposits (from the interaction of hot pyroclastic material and snow and ice) on the flanks as well as ashfall on the SW and N flanks. A smaller explosion at 0710 generated an ash plume that rose 4.5 km (14,800 ft) a.s.l. Low-level ash emissions continued during the morning based on webcam images and pilot reports.

Seismic tremor amplitude began increasing at around 1700 and remained elevated. An ash plume at an altitude of 4.6 km (15,000 ft) a.s.l. and drifting SSE was visible in a satellite image at 2100. AVO stated that activity had intensified. At 2357 AVO raised the Aviation Color Code to Red and noted that seismicity had remained elevated for over six hours and explosion signals were frequently detected by regional infrasound (pressure sensor) networks. A continuous ash plume extended more than 125 km SSE at an altitude of 4.9 km (16,100 ft) a.s.l., though some of the explosions sent ash plumes as high as 6 km (19,700 ft) a.s.l. Strongly elevated surface temperatures were observed in satellite data during 15-16 July. By 0734 on 16 July explosive activity had declined and seismicity had significantly declined. The Aviation Color Code was lowered to Orange. A remnant ash cloud drifted about 500 km SE before dissipating. Lava continued to erupt at the summit during 16-17 July and produced strongly elevated surface temperatures visible in satellite images. Lava effusion increased at 0100 on 18 July, shown by elevated surface temperatures identified satellite data, increasing seismic tremor, and activity detected on regional infrasound arrays. Activity again intensified and at 0700 a rapidly expanding ash cloud was visible drifting SSE, eventually reaching 9.1 km (30,000 ft) a.s.l. The Aviation Color Code was raised to Red and the Volcano Alert Level was raised to Warning. A Volcano Observatory Notice to Aviation (VONA) issued at 0837 noted that the plume was rising to 7.3 km (24,000 ft) a.s.l. based on recent pilot observations. By 0930 the main ash plume had detached. The eruption gradually declined, so at 1208 the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. Continuing ash emissions generated plumes that drifted S at altitudes below 3 km (10,000 ft) a.s.l.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 July-11 July 2023 Cite this Report

AVO reported that intermittent tremor and low-frequency earthquakes recorded at Shishaldin over the past week had gradually become more regular and consistent during 10-11 July. Strongly elevated surface temperatures at the summit were identified in satellite images during 10-11 July. The Volcano Alert Level was raised to Advisory (the second level on a four-level scale) and the Aviation Color Code was raised to Yellow (the second color on a four-color scale) at 1439 on 11 July, but AVO noted that the increased activity may or may not lead to an eruption.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 October-26 October 2021 Cite this Report

AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 20 October AVO changed both the Aviation Color Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with webcams, satellite data, remote infrasound, seismic, and GPS networks.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

31 March-6 April 2021 Cite this Report

AVO reinstated the Green Aviation Color Code and the Normal Volcano Alert Level for Shishaldin on 2 April, after several seismic stations again became operational following a months-long outage, thus improving the observatory’s monitoring capability.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 January-19 January 2021 Cite this Report

AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 15 January AVO changed both the Aviation Color Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with local webcams, satellite data, and remote infrasound, seismic, and lightning networks.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

24 June-30 June 2020 Cite this Report

On 24 June AVO reported that seismicity at Shishaldin had decreased to background levels. Additionally, satellite images showed no new lava in the crater area, typical surface temperatures, and minor steaming. The Volcano Alert Level was lowered to Normal and the Aviation Color Code was lowered to Green.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 April-21 April 2020 Cite this Report

On 16 April AVO reported that seismicity at Shishaldin had decreased during the past two weeks, though it remained slightly above background levels. Additionally, satellite images showed no new lava nor changes in the crater area, and a decrease in surface temperatures. 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)

8 April-14 April 2020 Cite this Report

AVO reported elevated seismicity at Shishaldin during 8-13 April characterized by occasional low-frequency earthquakes. Minor steaming from the summit crater was sometimes seen in satellite and webcam data. A small thermal anomaly was visible in satellite data during 8-9 April. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 April-7 April 2020 Cite this Report

AVO reported elevated seismicity at Shishaldin during 1-7 April characterized by weak continuous tremor and occasional low-frequency earthquakes. The webcam recorded steam plumes rising from the summit crater on 1 April. Weakly elevated surface temperatures were visible in satellite images on a few days. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 March-31 March 2020 Cite this Report

AVO reported elevated seismicity at Shishaldin during 25-31 March characterized by continuous low-level tremor. Steam-and-gas plumes rising from the summit crater were occasionally recorded by the webcam and identified in satellite images. Weakly- to- moderately elevated surface temperatures were identified in satellite images during 29-30 March. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 March-24 March 2020 Cite this Report

AVO reported that seismicity at Shishaldin was characterized as near-continuous tremor during 18-20 March and continuous tremor during 21-24 March. Steam-and-gas plumes rising from the summit crater were recorded daily by the webcam and sometimes identified in satellite images. Elevated surface temperatures, consistent with lava in the summit crater, were also identified in 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)

11 March-17 March 2020 Cite this Report

Lava and a possible new cone in Shishaldin’s summit crater were visible in a satellite image on 14 March prompting AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. Weak but elevated seismicity was also recorded along with small explosion signals during 14-17 March. Elevated surface temperatures, consistent with lava in the summit crater, were identified in satellite images during 15-17 March. A small steam plume rising from the summit crater was visible in a webcam image on 17 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 February-11 February 2020 Cite this Report

On 6 February AVO reported that seismicity at Shishaldin decreased during the previous week (though remained slightly above background levels), along with the surface temperatures at the summit identified in satellite data. AVO lowered the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory since the eruption appeared to have paused or ceased.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 January-4 February 2020 Cite this Report

AVO reported that seismic activity at Shishaldin remained above background levels during 29 January-4 February. Weakly- to moderately-elevated surface temperatures were sometimes identified in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 January-28 January 2020 Cite this Report

AVO reported that seismic activity at Shishaldin remained above background levels during 22-28 January. Elevated surface temperatures continued to be identified in satellite images, though became weak during 26-28 January. Infrasound data suggested that minor explosions were occurring at the summit during 22-23 January. Small steam plumes from the summit were visible on 22, 23, and 26 January. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 January-21 January 2020 Cite this Report

AVO reported that after almost a week of relatively quiet conditions at Shishaldin, during 16-17 January seismicity began to climb and the temperature of the thermal anomaly slightly increased. Activity intensified at 0030 on 19 January and by around 0630 the plume became more ash-rich. By around 0828 the ash plume rose to 6.1 km (20,000 ft) a.s.l. and drifted 150 km E, prompting AVO to raise the Aviation Color Code to Red and the Volcano Alert Level to Warning. Lava flows descended the NE and N flanks and generated lahars. By 1530 seismicity abruptly decreased, though around the same time the robust steam-and-ash plume (visible to pilots and in webcam and satellite images) rose as high as 9.1 km (30,000 ft) a.s.l. and continued to drift 150 km SSE. Minor amounts of ash fell in False Pass. Ash emissions had significantly declined by 2200 and seismicity was low; the Aviation Color Code was lowered to Orange and the Volcano Alert Level was lowered to Watch just after midnight the next morning. A detached volcanic cloud was identified in satellite images drifting ESE over the Pacific Ocean. During 20-21 January elevated surface temperatures were identified in satellite images, though the N-flank flow was not active. Seismicity remained above background levels, and coincided with detections in infrasound data that suggested small explosions at the vent. Steaming from the summit was visible in webcam images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 January-14 January 2020 Cite this Report

AVO summarized the 7 January eruptive activity at Shishaldin, characterizing the period of activity during 0500-1200 as the most sustained explosive activity of the eruptive sequence so far. Ash plumes drifted over 200 km ENE, were ash rich during 0900-1200, and caused several flight cancellations and minor ashfall in Cold Bay. Elevated surface temperatures continued to be identified in satellite images during 7-10 January, indicating lava effusion; seismicity decreased but remained above background levels. Satellite images acquired during 10-14 January showed weak surface temperatures, indicated cooling lava; seismicity remained above background levels.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 January-7 January 2020 Cite this Report

AVO reported that the eruption at Shishaldin continued during 1-7 January. Seismicity was low during 1-2 January and elevated surface temperatures identified in several satellite images indicated continuing lava effusion. Seismicity began increasing at 0930 on 3 January and within several hours a brief period of sustained ash emissions produced plumes that rose as high as 8.2 km (27,000 ft) a.s.l. and drifted about 120 km SE. The ash plume produced minor amounts of volcanic lightning. Seismicity declined abruptly after the event. Satellite images acquired the next day showed no noteworthy activity; ash deposits from the day before mantled the upper flanks, lahars on the upper parts of the edifice and on the SW flank were visible, and lava flows on the upper NW and NE flanks were 1-2 km long. During 5-6 January seismicity was low but above background levels and elevated surface temperatures were visible in satellite images. A photo taken from Cold Bay (93 km NE) on 6 January showed glowing lava flows on the flank.

Seismicity increased at around 0500 on 7 January and was followed by observations of an ash plume drifting NE at an altitude of about 5.8 km (19,000 ft) a.s.l. Seismicity then decreased for a few hours. Another episode of elevated seismicity was accompanied by an increase in the altitude of the ash plume; it rose to 7.6 km (25,000 ft) a.s.l. and seemed to have a denser ash content. The Aviation Color Code was raised to Red and the Volcano Alert Level was raised to Warning. Volcanic lighting was detected in the cloud and volcanic infrasound signals were detected at regional stations. Seismcity significantly decreased around 1200 and remained low. Later that day the Aviation Color Code was lowered to Orange and the Volcano Alert Level was lowered to Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 December-31 December 2019 Cite this Report

AVO reported that the eruption at Shishaldin continued during 25-31 December. Seismicity was elevated with weak explosions recorded by the network during 26-27 December. The seismicity decreased to relatively low levels on 27 December and remained low through 31 December. Strongly elevated surface temperatures were periodically identified in satellite images, indicating continuing lava effusion; images acquired during 25-26 December confirmed a 1.5-km-long lava flow on the NW flank and tephra deposits on the upper flanks. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 December-24 December 2019 Cite this Report

AVO reported that the eruption at Shishaldin continued during 18-24 December. Elevated surface temperatures were identified in satellite images, though clouds sometimes prevented views. Seismicity remained elevated and was characterized by ongoing tremor and periodic weak explosions. Satellite imagery indicated that the active summit cone had grown after collapsing the week before. Minor ash emissions drifted S on 19 December and E at 4.6 km (15,000 ft) a.s.l. on 21 December. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 December-17 December 2019 Cite this Report

AVO reported that seismicity at Shishaldin remained elevated during 10-11 December; low-level tremor was detected along with three small explosions. Elevated surface temperatures were identified in satellite images and a steam plume drifting from the summit was visible in webcam images. A short-lived explosion began at 0710 on 12 December and lasted about three minutes, coincident with a three-minute long period of elevated tremor. The event generated an ash plume that rose to altitudes of 6.1-7.6 km (20,000-25,000 ft) a.s.l., drifted almost 85 km/hour WNW, and then dissipated a few hours later. Three lightning strokes were detected between 0715 and 0717. The explosion may have collapsed the summit spatter cone. Highly elevated surface temperatures were visible in satellite images during 12-13 December, and the webcam showed nighttime incandescence and a robust steam plume emanating from the summit. Seismicity remained elevated through 16 December and elevated surface temperatures continued to be detected. A plume appearing to contain ash drifted from the summit on 14 December. A lava flow was reported by a pilot on 16 December; the next day satellite images showed a 2-km-long flow on the NW flank. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 December-10 December 2019 Cite this Report

AVO reported that elevated surface temperatures at Shishaldin were identified in satellite images during 3-4 December consistent with lava effusion, and a pilot confirmed active lava flows on the flank. Continuous tremor was recorded by the seismic network during 4-5 December. Seismicity, including Strombolian explosion signals, continued to increase until 2100 on 5 December and then afterwards was characterized by episodic tremor bursts and occasional Strombolian activity. Intermittent, very minor, and low-level ash or steam emissions near the summit and along the N flank were visible in clear webcam views on 5 December. A new lava flow had traveled 1.4 km down the NW flank. The eruption either slowed or paused during 6-7 December as evidenced by decreased seismicity and slightly elevated surface temperatures in satellite data. Temperatures again increased and were slightly elevated during 7-9 December, likely signifying renewed lava effusion. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

27 November-3 December 2019 Cite this Report

AVO reported that seismic levels at Shishaldin were variable but elevated during 26 November-3 December. Weather clouds sometimes obscured satellite image views and mostly prevented webcam views, though elevated surface temperatures were still visible in multiple satellite images. An active 1.5-km-long lava flow on the NW flank was visible in satellite images on 1 December. Continuous tremor transitioned to episodic bursts during the morning of 2 December, but by 3 December a decrease in seismic activity and surface temperatures suggested another pause in lava effusion. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 November-26 November 2019 Cite this Report

AVO reported that increased seismicity and higher surface temperatures at Shishaldin during 19-20 November indicated elevated eruptive activity. Seismicity abruptly dropped at 0340 on 20 November and remained low, heralding another pause in activity. Tremor and surface temperatures remained low through 23 November. Seismicity again increased during 24-25 November and small explosions were detected in local and regional infrasound stations. Strongly elevated surface temperatures were observed in multiple satellite images. A partial collapse of the summit cone sometime around 1430 on 24 November produced a pyroclastic flow that traveled as far as 3 km down the NW flank. A new lava flow on the NW flank was several hundred meters long. Seismicity decreased but remained elevated during 25-26 November. Strongly elevated surface temperatures were identified in multiple satellite images, and incandescence from the summit was occasionally visible in web camera images overnight. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 November-19 November 2019 Cite this Report

AVO reported that the eruption at Shishaldin continued at variable levels during 13-19 November. Seismicity increased during 13-14 November, and elevated surface temperatures were visible in satellite and webcam data. Minor ash emissions were visible and likely resulting from spatter cone collapses. Lava and debris flows had not advanced since 8 November; lava flows had traveled as far as 1.2 km and a large branched network of debris flows extended at least 5.5 km NE. Strongly elevated surface temperatures and a steam plume drifting more than 100 km SE were visible on 15 November. An incandescent lava flow on the NE flank was recorded in webcam images. Activity during 17-18 November was characterized by low seismic tremor and weakly-to-moderately elevated surface temperatures, consistent with cooling lava flows. Seismicity and surface temperatures again increased during 18-19 November. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 November-12 November 2019 Cite this Report

AVO reported that the eruption at Shishaldin continued at variable levels during 5-12 November. Periods of high-amplitude tremor during 5-6 November were likely related to increased lava effusion and fountaining, though weather clouds prevented visual confirmation. Intermittent advancement of active lava flows and lahars on the N flank were confirmed in RADAR data, and by 7 November the lava flow was 1.3 km long and the debris flow runout was 5 km. Seismic tremor was low during 8-9 November suggesting lava effusion was less likely; weather cloud cover continued to obscure views, though elevated surface temperatures were sometimes detected during brief periods of clear weather. Activity significantly increased during 10-11 November with lava fountaining visible in webcam views throughout the evening and night. Strongly elevated surface temperatures at the summit and along the flanks were visible in satellite data. Ash emissions reported by pilots and visible on webcam images rose as high as 3.7 km (12,000 ft) a.s.l. and drifted N. Activity decreased during 11-12 November. Strongly elevated surface temperatures were consistent with cooling lava flows. Seismicity decreased during the evening of 11 November and remained low. Minor steam-and-ash emissions were visible in webcam images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

30 October-5 November 2019 Cite this Report

AVO reported that by 28 October two stalled lava flows extended as far as 1.8 km down Shishaldin’s NW flank, lahars had traveled at least 4 km down the NW flank, and trace ash deposits on the N flank were identified in satellite images. Activity paused during 29-30 October but resumed on 31 October. Numerous small explosions were detected by the local seismic network during 31 October-1 November and incandescence was visible in webcam images. There was no evidence of active lava flows outside of the summit crater. During 1-2 November seismicity remained elevated characterized by periods of high-amplitude tremor. Small explosions were recorded in seismic and infrasound data. Elevated surface temperatures were detected in satellite images and incandescence was observed in webcam images overnight. A pilot observed a lava flow in the morning of 2 November. Sporadic incandescence recorded by the webcam overnight during 2-3 November suggested minor explosive activity and/or lava fountaining. On 3 November lava overflowed the summit crater and traveled at least 400 m down the NW flank and 300 m down the SE flank. By 4 November the flow on the NW flank had branched and lengthened to 1 km. Lahars were as long as 2 km on the N and S flanks. Spatter deposits from explosions or fountaining were visible on the summit cone. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 October-29 October 2019 Cite this Report

Pilot and local observations as well as webcam views all indicated that the incandescence at Shishaldin’s summit crater was from low-level Strombolian activity during 21-22 October. Seismicity and infrasound signals were consistent with low-level eruptive activity, and a steam plume was persistent. By 23 October lava had filled the crater and during 23-24 October overflowed the N crater rim. A 200-m-long lava flow on the N flank melted snow and caused a lahar which traveled 2.9 km and stopped at about 1,230 m elevation. A smaller lava flows caused a 1-km-long lahar to descend the NE flank. Spatter accumulated around the crater rim and melted snow. On 25 October AVO noted that trace ash deposits had extended at least 8.5 km SE.

Low-level eruptive activity continued during 26-29 October. Seismicity remained elevated, with periods of high-amplitude tremor. Small explosions were recorded during 27-28 October. A satellite image from 28 October showed a 850-m-long SWIR anomaly on the NW flank from a lava flow. A central spatter cone was visible. Spatter deposits on the snow at the upper flanks was evident, and tephra deposits extended about 2.5 km N. The lahar on the NW flank branched extensively at lower elevations and was at least 5 km long. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

16 October-22 October 2019 Cite this Report

On 17 October AVO raised the Aviation Color Code for Shishaldin to Orange and the Volcano Alert Level to Watch noting that new lava effusion in the summit crater had begun on 13 October. Weather clouds had mostly prevented views of the crater during 12-18 October; elevated surface temperatures were detected during 13 and 17-20 October. A steam plume was visible in webcam images on 19 October.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 September-1 October 2019 Cite this Report

On 26 September AVO reported that seismicity at Shishaldin had decreased during the previous few weeks to levels slightly above background. Satellite images indicated decreased surface temperatures at the summit over the same period and showed collapse and slumping of the floor of the summit crater, suggesting a withdrawal of magma. Tiltmeter data suggested that the collapse may have occurred on 19 September. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 September-24 September 2019 Cite this Report

AVO reported that during 18-24 September low-level tremor at Shishaldin continued to be recorded, along with elevated surface temperatures at the summit crater visible in satellite images when views were not obscured by clouds. The data suggested ongoing, slight growth of the scoria cone and lava flows within the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 September-17 September 2019 Cite this Report

Low-level lava fountaining and minor explosive activity within Shishaldin’s summit crater was last observed on 17 August and likely continued during 11-17 September; continuous tremor was recorded by the seismic network and elevated surface temperatures were visible in satellite images. The webcam possibly recorded a steam emission on 16 September. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 September-10 September 2019 Cite this Report

Low-level lava fountaining and minor explosive activity within Shishaldin’s summit crater was last observed on 17 August and likely continued during 4-10 September; continuous tremor was recorded by the seismic network and moderately-elevated surface temperatures were visible in satellite images. Elevated surface temperatures on the upper SE flank suggested that minor amounts of lava spatter may have extended beyond the summit crater; clear webcam images showed no evidence of hot deposits on the upper flank the next day. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 August-3 September 2019 Cite this Report

Low-level lava fountaining and minor explosive activity within Shishaldin’s summit crater was last observed on 17 August and likely continued during 28 August-2 September; continuous tremor was recorded by the seismic network and moderately-elevated surface temperatures were visible in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

21 August-27 August 2019 Cite this Report

AVO reported that during 21-28 August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were often visible in satellite images. The spatter cone in the crater had grown and partially filled the summit crater. NOAA scientists took video of the eruption during an overflight on 17 August and noted repetitive minor explosive activity within the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 August-20 August 2019 Cite this Report

AVO reported that during 14-20 August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were visible in infrared satellite images. The spatter cone in the crater had grown and partially filled the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 August-13 August 2019 Cite this Report

AVO reported that during 7-13 August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were visible in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

31 July-6 August 2019 Cite this Report

AVO reported that satellite images of Shishaldin acquired on 28 July showed a small spatter cone with lava flows in the summit crater. During 31 July-6 August continuous weak tremor was recorded by the seismic network and elevated surface temperatures were sometimes visible in satellite images. A small steam plume was observed in a few satellite and web camera images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

24 July-30 July 2019 Cite this Report

On 23 July field crews observed minor spattering and surface lava flows in Shishaldin’s summit crater during an overflight, prompting AVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch. Elevated surface temperatures were observed in multiple satellite images during 24-30 July, though views were sometimes obscured by weather clouds. Nearly continuous weak seismic tremor was detected, and occasional infrasound signals consistent with small Strombolian explosions were recorded during 26-27 July.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

17 July-23 July 2019 Cite this Report

AVO reported that weak tremor continued to be recorded at Shishaldin during 17-23 July and elevated surface temperatures were observed in multiple satellite images. Cloudy conditions typically obscured webcam views of the volcano, but when conditions were clear a small steam plume at the summit was visible. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

10 July-16 July 2019 Cite this Report

AVO increased the Aviation Color Code for Shishaldin to Yellow and the Volcano Alert Level to Advisory on 12 July following several weeks of increasing seismicity and elevated temperatures in the summit crater identified in satellite images. In addition incandescence in the crater was visible during an overflight. Seismic tremor continued to be elevated at least through 16 July.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 February-13 February 2018 Cite this Report

On 7 February AVO reported that seismic and infrasound activity from Shishaldin declined to background levels during the previous month, prompting the observatory to lower the Aviation Color Code to Green and the Volcano Alert Level to Normal.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 December-19 December 2017 Cite this Report

AVO reported that seismic and infrasound data from Shishaldin continued to indicate elevated activity during 13-19 December. Robust steaming was recorded by a webcam during 13-14 December; ice and poor weather conditions prevented views during the rest of the period. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 December-12 December 2017 Cite this Report

AVO increased the Aviation Color Code for Shishaldin to Yellow and the Volcano Alert Level to Advisory on 6 December following several weeks of increasing seismicity and pressure waves recorded by infrasound sensors. Continuous infrasound waves were detected for more than 10 hours on instruments located in Sand Point, ~230 km E. Steam emissions visible in satellite and webcam images during 5 and 8-12 December were rising hundreds of feet above the summit crater. The steam emissions were occasionally accompanied by infrasound signals indicating episodes of short-duration energetic gas emissions and/or small explosions.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

9 March-15 March 2016 Cite this Report

On 10 March AVO reported that there had been a continual decrease in thermal activity at Shishaldin over the past several months; no anomalous activity had been observed in several clear satellite images since 13 January, when moderately elevated surface temperatures were detected. Airwaves generated by low-level explosive degassing had not been detected in infrasound data since 7 February. Low-amplitude seismic tremor was at background levels. The Aviation Color Code was lowered to Green and the Volcano Alert Level was lowered to Normal.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 November-24 November 2015 Cite this Report

AVO reported that no anomalous activity at Shishaldin had been observed in satellite data since weakly elevated surface temperatures were detected on 16 October. In addition, low-amplitude seismic tremor continued but was likely not indicative of a continuing eruption. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 November-17 November 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 11-17 November, indicating that low-level eruptive activity confined to the summit crater continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 November-10 November 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 4-10 November, indicating that low-level eruptive activity confined to the summit crater continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 October-3 November 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 28 October-2 November, indicating that low-level eruptive activity confined to the summit crater continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

21 October-27 October 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 21-27 October, indicating that low-level eruptive activity confined to the summit crater continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 October-20 October 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 14-20 October, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations; weakly elevated surface temperatures were detected in satellite images on 16 October. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 October-13 October 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 7-13 October, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations; minor steam emissions were visible on 7 October, and weakly elevated surface temperatures were detected in satellite images during 7-8 October. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

30 September-6 October 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 30 September-4 October, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 September-29 September 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 23-29 September, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations; weakly elevated surface temperatures were detected in satellite images on 23 September. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

16 September-22 September 2015 Cite this Report

AVO reported that seismicity at Shishaldin was only slightly above background levels during 16-22 September. No activity was observed in satellite or webcam images during clear periods. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

9 September-15 September 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 9-15 September, indicating that low-level eruptive activity confined to the summit crater continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

2 September-8 September 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 2-8 September, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations; elevated surface temperatures were periodically detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

26 August-1 September 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 26 August-1 September, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover often prevented satellite and webcam observations; elevated surface temperatures were periodically detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

19 August-25 August 2015 Cite this Report

AVO reported that on 18 August a field crew conducting gas measurements at Shishaldin observed a low-level plume from the summit drifting several kilometers downwind. Seismicity continued to be elevated over background levels during 19-25 August indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover mostly prevented satellite and webcam observations; elevated surface temperatures were occasionally detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

12 August-18 August 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 12-18 August, indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover mostly prevented satellite and webcam observations; elevated surface temperatures were detected in satellite images on 13 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 August-11 August 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 5-11 August indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover sometimes prevented satellite and webcam observations; elevated surface temperatures were sometimes detected in satellite images and steaming from the crater was occasionally recorded by the webcam. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 July-4 August 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 28 July-4 August indicating that low-level eruptive activity confined to the summit crater continued. Cloud cover sometimes prevented satellite and webcam observations; elevated surface temperatures were sometimes detected in satellite images. Satellite images detected a 24-km-long steam plume drifting SE on 28 July and vigorous steaming and plumes drifting SW on 31 July. A steam plume was recorded by the webcam on 2 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 July-28 July 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 22-28 July, indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover prevented satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 July-21 July 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 15-21 July indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover prevented satellite and webcam observations. Elevated surface temperatures were detected in satellite images during 19-20 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 July-14 July 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 8-14 July indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover prevented satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 July-7 July 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 1-7 July indicating that low-level eruptive activity confined to the summit crater likely continued. Although cloud cover often prevented visual observations, webcam images showed periodic steaming, and ash at the summit during 2-3 July. Elevated surface temperatures at the summit were detected in satellite images on 3 and 7 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

24 June-30 June 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 24-30 June, indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images. Webcam images showed ash deposits around the summit crater rim on 29 and 30 June. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

17 June-23 June 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 17-23 June, indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images, and minor steaming was recorded by the webcam. On 18 June pilot and satellite observations indicated a weak ash plume rising around 100 m above the summit crater, resulting in ash deposits on the upper flanks. Weak ash emissions were also visible with the webcam the next day. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

10 June-16 June 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 10-16 June indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images, and minor steaming was recorded by the webcam. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

3 June-9 June 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 3-9 June, indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images, and minor steaming was recorded by the webcam. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

27 May-2 June 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 27 May-2 June, indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images, and minor steaming was recorded by the webcam during 27-28 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 May-26 May 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 20-26 May indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 May-19 May 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 13-19 May, indicating that low-level eruptive activity confined to the summit crater likely continued. On 15 May a low-level vigorous gas-and-steam plume possibly containing ash was recorded by the webcam. Elevated surface temperatures were detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 May-12 May 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 6-12 May indicating that low-level eruptive activity confined to the summit crater likely continued. Periodically, elevated temperatures in the crater were detected and steaming was recorded by the webcam, although cloud cover sometimes prevented views of the volcano. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 April-5 May 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 29 April-5 May indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. Weakly elevated temperatures in the crater were detected on 4 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 April-28 April 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 22-28 April, indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. Slight steaming was recorded by the webcam on 26 April and elevated temperatures were detected in satellite images during 27-28 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 April-21 April 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 15-21 April indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. On 16 April the webcam periodically recorded a white steam plume rising about 500 m above the summit. Several pilot reports indicated ash emissions, prompting a SIGMET, however no ash was visible in satellite or webcam images, and seismicity remained unchanged. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 April-14 April 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 8-14 April. They interpreted those data as indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 April-7 April 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 1-7 April indicating that low-level eruptive activity confined to the summit crater likely continued. Highly elevated surface temperatures in the crater were detected during 1-3 April, suggesting the presence of lava within the crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 March-31 March 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 25-31 March, indicating that low-level eruptive activity confined to the summit crater likely continued. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. Vigorous steaming at the summit was visible during 28 and 30-31 March; steam plumes, also reported by a pilot, rose several hundred feet above the crater on 30 March, and on 31 March observers on a Coast Guard ship reported that a steam-rich plume drifted 15-30 km S. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 March-24 March 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 18-24 March, indicating that low-level eruptive activity confined to the summit crater likely continued. Nothing significant was observed in mostly cloudy satellite and web camera images; slight steaming at the summit was visible during 22-23 March. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 March-17 March 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 11-17 March, indicating that low-level eruptive activity confined to the summit crater likely continued. Minor steaming from the summit was observed in webcam images on 11 March. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 March-10 March 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 4-10 March. Elevated surface temperatures were sometimes detected in satellite images. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 February-3 March 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 25 February-3 March. Elevated surface temperatures, sometimes that were highly elevated, were detected in satellite images almost daily. The webcam recorded minor degassing on 25 February and a low-level plume during 28 February-1 March. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 February-24 February 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 18-24 February. Cloud cover often prevented webcam and satellite-image views of the volcano. Weakly elevated surface temperatures were detected in satellite images during 22-24 February. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 February-17 February 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 11-17 February. Elevated surface temperatures were observed in satellite images on most days, and minor steam emissions were recorded by the web cam on 11 February. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 February-10 February 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 4-10 February. Elevated surface temperatures were observed in satellite images on most days, and minor steam emissions were recorded by the web cam during 6-9 February. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 January-3 February 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 28 January-3 February. Nothing significant was observed in mostly cloudy satellite and web camera images, although minor steaming from the summit was recorded by the webcam during 30 January-3 February. During 31 January-3 February elevated surface temperatures were observed in satellite images, and during 1-2 February low-level ash emissions drifted WSW. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

21 January-27 January 2015 Cite this Report

AVO reported that on 21 January webcam images taken in partly cloudy conditions at Shishaldin possibly showed a dusting of fresh ash on the snowy upper flanks. During 21-22 January seismicity continued to be slightly elevated over background levels. Strongly elevated temperatures at the summit detected in overnight satellite images were consistent with possible lava in the crater. Clear webcam views during 23-25 January showed a small steam plume, indicating that the current activity was mostly contained in the deep summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 January-20 January 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 14-20 January. Nothing significant was observed in clear-to-cloudy satellite and web camera images, although weakly elevated temperatures were detected in one satellite image on two different days. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 January-13 January 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 7-13 January. Nothing significant was observed in clear-to-partly cloudy satellite and web camera images. In a report from 9 January AVO noted that a small number of air-pressure waves from minor explosions within the summit crater were detected in seismic data intermittently during the previous week; there was no evidence of ash emissions outside of the crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

31 December-6 January 2015 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 31 December-6 January. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. Minor steam emissions were occasionally recorded by the webcam. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

24 December-30 December 2014 Cite this Report

AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 23-30 December. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

17 December-23 December 2014 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated during 17-23 December. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. Occasional steam emissions were recorded by the web camera. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

10 December-16 December 2014 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated during 10-16 December. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. A low-level lava eruption was likely still occurring within the summit crater of the volcano. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

3 December-9 December 2014 Cite this Report

AVO reported that seismicity at Shishaldin continued to be elevated during 3-9 December. Thermal anomalies were often detected in satellite images during periods of clear weather. Webcam images on 9 December showed minor steam emissions. A low-level lava eruption was likely still occurring within the summit crater of the volcano. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

26 November-2 December 2014 Cite this Report

AVO reported that although seismicity at Shishaldin continued to be elevated, levels declined during 26 November-2 December. Elevated crater temperatures were detected in satellite images during periods of clear weather from 26 to 28 November. A low-level lava eruption was likely still occurring within the summit crater of the volcano. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

19 November-25 November 2014 Cite this Report

AVO reported that intermittent volcanic tremor at Shishaldin continued to be detected during 19-23 November. Elevated crater temperatures were detected in satellite images during periods of clear weather; thermal anomalies were reported during 21-22 November. Seismic activity increased sharply on 24 November, suggesting that the eruption had intensified. Strong thermal anomalies near the summit were detected in satellite images. On 25 November seismicity remained elevated and strongly elevated surface temperatures continued to be detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

12 November-18 November 2014 Cite this Report

AVO reported that seismicity at Shishaldin remained elevated during 12-18 November. Elevated crater temperatures were detected in satellite images during periods of clear weather. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 November-11 November 2014 Cite this Report

AVO reported that seismicity at Shishaldin remained elevated during 5-11 November. Satellite and webcam views showed nothing unusual; temperatures at the summit were elevated on 5 November. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 October-4 November 2014 Cite this Report

AVO reported that mostly cloudy satellite and webcam views showed nothing unusual at Shishaldin during 29 October-4 November, although the low-level eruptive activity continued. Periods of tremor were detected and overall seismicity remained elevated. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 October-28 October 2014 Cite this Report

AVO reported that partly cloudy satellite images and mostly cloudy webcam views showed nothing unusual at Shishaldin during 21-24 October. Seismicity increased on 25 October, and was followed by a tremor event and elevated surface temperatures detected at the summit in satellite images. Tephra deposits at the summit were noted in clear webcam images on 26 October, indicating that the event was energetic enough to eject material onto the flank from a depth of several hundred meters within the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 October-21 October 2014 Cite this Report

AVO reported that, although cloud cover often obscured views of Shishaldin during 15-21 October, seismicity indicated that a low-level eruption was likely continuing. Elevated surface temperatures at the summit were periodically detected in cloud-free satellite images. Tremor and ground-coupled airwaves from small explosions were occasionally detected in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 October-14 October 2014 Cite this Report

AVO reported that, although cloud cover often obscured views of Shishaldin during 8-14 October, seismicity indicated a low-level eruption was likely continuing. Strongly elevated surface temperatures at the summit were periodically detected in cloud-free satellite images during 10-11 and 13-14 October. Tremor and ground-coupled airwaves from small explosions were occasionally detected in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

1 October-7 October 2014 Cite this Report

AVO reported that seismicity at Shishaldin indicated that a low-level eruption likely continued during 1-7 October. Strongly elevated surface temperatures at the summit were periodically detected in satellite images; cloud cover sometimes obscured satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

24 September-30 September 2014 Cite this Report

AVO reported that, although cloud cover sometimes obscured views of Shishaldin during 24-30 September, seismicity indicated that a low-level eruption was possibly continuing. Elevated surface temperatures at the summit were periodically detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

17 September-23 September 2014 Cite this Report

AVO reported that, although cloud cover sometimes obscured views of Shishaldin during 17-22 September, seismicity indicated that a low-level eruption was possibly continuing. Elevated surface temperatures at the summit were periodically detected in satellite images. Minor steam emissions were recorded by the web cam on 17 September. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

10 September-16 September 2014 Cite this Report

AVO reported that low-level seismicity and eruptive activity continued from Shishaldin during 10-16 September. Observations were frequently restricted due to cloudy conditions, although elevated temperatures were observed on 15 September in one satellite image.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

3 September-9 September 2014 Cite this Report

AVO reported that low-level seismicity and eruptive activity continued from Shishaldin during 3-7 September. When weather conditions were favorable, satellite images detected elevated surface temperatures. Observations were restricted on 8-9 September due to cloudy conditions.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

27 August-2 September 2014 Cite this Report

AVO reported that during 27 August-2 September low-level eruptive activity continued at Shishaldin volcano. On 28 August a thermal feature was observed and on 31 August a small steam plume was seen in satellite images. During clear weather on 1 September no activity was observed. On 2 September elevated surface temperatures at the summit crater were noted from satellite data. Clouds prevented observations the other days of the week. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

20 August-26 August 2014 Cite this Report

AVO reported that during 20-26 August low-level eruptive activity continued at Shishaldin volcano. A steam and gas plume was visible in web camera and satellite images occasionally during the week. On 20 August satellite images showed a steam plume extending 60 km N of the volcano. On 23 August a pilot reported a steam-and-ash plume rose about 300 m (1,000 ft) above the summit and drifted NE. On 20-22 and 26 August elevated surface temperatures at the summit were detected in clear satellite views. Infrasound sensors located in Dillingham and on Akutan Island detected sound waves from the direction of Shishaldin that were consistent with low-level eruptive activity. No significant activity noted in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

13 August-19 August 2014 Cite this Report

AVO reported that during 13-19 August eruptive activity continued at Shishaldin volcano. Infrasound sensors located at Dillingham and on Akutan Island detected sound waves from the direction of Shishaldin that are consistent with low-level activity at the volcano. On 13 August a pilot reported a low-level plume from Shishaldin. On the evening of 16 August web camera views showed a steam and gas plume. On 17-19 August elevated surface temperatures were detected in partly cloudy satellite views. Other days satellite and web camera views were obscured by weather. No significant activity was noted in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 August-12 August 2014 Cite this Report

AVO reported that during 6-12 August low-level eruptive activity continued at Shishaldin volcano. Web camera and satellite images showed the volcano was mostly cloudy over the past week, but intermittent web camera views showed a steam plume above the summit. On 9-10 August sound waves were detected from the direction of Shishaldin on infrasound sensors in Dillingham, consistent with the low-level activity. On 10 August an area of hot, glowing material was observed in the crater during an overflight of the Shishaldin summit. On 11 August elevated surface temperatures were observed in the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

30 July-5 August 2014 Cite this Report

AVO reported that during 30 July-5 August low-level eruptive activity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected from satellite data most days except for cloudy conditions 4-5 August. Steaming from the summit crater was visible in web cam images 30 July-1 August and 5 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 July-29 July 2014 Cite this Report

AVO reported that during 23-29 July low-level eruptive activity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected daily from satellite data. On 26 July satellite and web camera images showed trace dustings of ash over fresh snow in the immediate vicinity of the crater. Web camera images showed short dark streaks of possible debris flow deposits extending from the summit crater on the southeast flank, possibly the result of the melting of snow and ice near the summit due to the increased temperatures in the vicinity of the crater. Web camera and satellite images were mostly obscured due to clouds other days. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

16 July-22 July 2014 Cite this Report

AVO reported that during 16-22 July low-level eruptive activity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected from satellite data daily, slightly increasing 18 July. Steaming from the summit crater was visible in satellite imagery on 16 July. Web-camera images were mostly obscured due to clouds. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

9 July-15 July 2014 Cite this Report

AVO reported that during 2-15 July low-level seismicity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected. A steam and gas plume was intermittently visible rising from the summit and drifting downwind, although satellite and web-camera images were mostly obscured due to clouds. On 9 July small explosions, probably within the summit cone, were detected on seismic and infrasound networks. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

25 June-1 July 2014 Cite this Report

AVO reported that during 25 June – 1 July, low-level seismicity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected. A steam and gas plume was intermittently visible rising from the summit and drifting downwind, although satellite and web-camera images have been mostly cloudy. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

18 June-24 June 2014 Cite this Report

AVO reported that Shishaldin’s low-level eruptive activity continued during 18-23 June and elevated surface temperatures were detected in satellite data (20-23 June). The volcano was frequently obscured by clouds and fog, but minor low-level steam plumes were observed in web camera images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 June-17 June 2014 Cite this Report

AVO reported that, although cloudy conditions frequently obscured webcam and satellite views of Shishaldin during 11-16 June, seismicity indicated that the low-level eruption continued. Strongly elevated surface temperatures at the summit were detected in satellite data on the morning of 16 June. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

4 June-10 June 2014 Cite this Report

AVO reported that, although cloud cover frequently obscured views of Shishaldin during 4-9 June, seismicity indicated that the low-level eruption continued. Elevated surface temperatures at the summit were detected in mostly cloudy satellite images during 7-9 June. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 May-3 June 2014 Cite this Report

AVO reported that, although cloud cover frequently obscured views of Shishaldin during 28 May-3 June, elevated surface temperatures at the summit were detected in satellite images, and minor steam emissions were observed in webcam images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

21 May-27 May 2014 Cite this Report

AVO reported that on most days during 21-27 May elevated surface temperatures at Shishaldin's summit were detected in satellite images, and minor steam emissions were observed in webcam images on 21 May. Cloud cover often prevented observations. Seismometers near the volcano detected brief explosion signals during 21-26 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 May-20 May 2014 Cite this Report

AVO reported that during 14-20 May elevated surface temperatures at Shishaldin's summit were detected in satellite images, and minor steam emissions were observed in webcam images. A report from 16 May noted that dark ash-covered snow near the summit was visible on an unspecified day during the past week. Seismometers near the volcano detected brief explosion signals during 17-20 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 May-13 May 2014 Cite this Report

AVO reported that although cloud cover occasionally prevented web-cam and satellite observations of Shishaldin's summit area during 7-13 May, periods of elevated surface temperatures and minor steaming were observed. A report from 9 May noted that dark ash-covered snow near the summit was visible on an unspecified day during the past week. A continuous “tremor-like” signal detected during 0430-0630 on 13 May coincided with a distinct increase in surface temperatures, possibly indicating a Strombolian eruption. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

30 April-6 May 2014 Cite this Report

AVO reported that although cloud cover occasionally prevented web-cam and satellite observations of Shishaldin's summit area during 30 April-6 May, periods of elevated surface temperatures and minor steaming were observed. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 April-29 April 2014 Cite this Report

AVO reported that although cloud cover occasionally prevented web-cam and satellite observations of Shishaldin's summit area during 23-29 April, periods of elevated surface temperatures and minor steaming were observed. No significant changes were detected in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

16 April-22 April 2014 Cite this Report

AVO reported that although cloud cover often prevented web-cam and satellite observations of Shishaldin's summit area during 16-22 April, weakly elevated surface temperatures and minor steaming were occasionally observed. No significant changes were detected in seismic data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

9 April-15 April 2014 Cite this Report

AVO reported that elevated surface temperatures over Shishaldin's summit area were detected in satellite images on most days during 9-15 April; cloud cover occasionally prevented observations. Ground-coupled air waves from small explosions detected by the seismic network decreased during 9-10 April. Minor ash deposits were observed several hundred meters down flanks. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

2 April-8 April 2014 Cite this Report

AVO reported that elevated surface temperatures over Shishaldin's summit area were detected in satellite images during 2-8 April. No activity was detected in the seismic data. The webcam showed a steam plume rising from the crater on 6 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

26 March-1 April 2014 Cite this Report

AVO reported that ground-coupled air waves from small explosions at Shishaldin's summit area were detected in seismic data during 25-27 March, although the energy and rate of occurrence both declined over that time. Elevated surface temperatures were identified in satellite images on 27 March. Based on the elevated surface temperatures and explosions persistent since 18 March AVO raised the Aviation Color Code to Orange and the Volcano Alert Level to Watch on 28 March. Analysis of the data showed that the temperatures were consistent with an eruption of lava within the summit crater. Web-camera images, satellite data, and pilot observations during the previous week indicated only minor steam emissions from the summit crater; there had been no evidence of ash emissions. Explosions were detected during 29-30 March; elevated surface temperatures were identified during 30-31 March.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

19 March-25 March 2014 Cite this Report

AVO reported that ground-coupled air waves from small explosions at Shishaldin's summit area were detected in seismic data during 19-25 March. Elevated surface temperatures were identified on most days during this period. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

12 February-18 February 2014 Cite this Report

AVO reported that no activity from Shishaldin was observed in party-to-mostly-cloudy satellite images during 12-18 February. The nearest working seismic station detected low seismicity. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 February-11 February 2014 Cite this Report

AVO reported that elevated surface temperatures in Shishaldin's summit crater were detected in satellite images during 5-6 February. No unusual seismicity was detected by the nearest working station off the flanks of the volcano. A possible ash-poor gas cloud was detected in satellite images beginning at 0645 on 7 February that may have been from a small explosion, too small to be detected by the seismometer but coinciding with a local tiltmeter signal. Satellite image analysis suggested that the short-lived cloud may have risen to an altitude of 7.6 km (25,000 ft) a.s.l. Elevated surface temperatures were not detected after the event, so very little if any hot material was ejected. During 9-11 February elevated surface temperatures were detected in satellite images and a tiltmeter 5.4 km SW of the volcano recorded a small signal. Clear or partly clear web cam images showed no activity. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

29 January-4 February 2014 Cite this Report

On 30 January, AVO raised the Aviation Color Code for Shishaldin to Yellow and the Volcano Alert Level to Advisory based on increased surface temperatures detected at the summit crater by satellite images over the previous few days, as well as increased steam emissions observed on 29 January in satellite and web-camera images. No steam emissions were observed during 30-31 January. Elevated surface temperatures were again detected on 1 February.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

14 October-20 October 2009 Cite this Report

On 19 October, AVO reported that recent clear satellite views of Shishaldin showed no activity; the last thermal anomaly was detected on 16 August. Seismicity was variable, but within background levels. The Aviation Color Code was lowered to Green and the Volcano Alert Level was lowered to Normal.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

8 July-14 July 2009 Cite this Report

On 10 July, AVO reported that a distinct thermal anomaly in Shishaldin's summit crater observed intermittently since January 2009 became more intense during the previous month. AVO raised the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. AVO also noted that seismicity had not increased, deformation was unchanged, and satellite observations showed no significant sulfur dioxide gas emissions. Some reports of steaming from the summit crater were received.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

11 February-17 February 2009 Cite this Report

AVO reported that seismic activity from Shishaldin had returned to background levels in December 2008 and remained low. On 3 February, a weak thermal anomaly was detected on satellite imagery. The Aviation Color Code was lowered to Green and the Volcano Alert Level was lowered to Normal on 11 February.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 January-13 January 2009 Cite this Report

AVO reported that thermal anomalies over Shishaldin's summit were detected in satellite imagery during 7-10 January. Clouds prevented observations on 11, 12, and 13 January. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

31 December-6 January 2009 Cite this Report

AVO reported that significant thermal anomalies over Shishaldin's summit were detected in satellite imagery during 5-6 January. Seismic activity had also increased slightly. AVO raised the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

6 February-12 February 2008 Cite this Report

Based on pilot reports, the Anchorage VAAC reported that a small ash plume from Shishaldin rose to an altitude of 3 km (10,000 ft) a.s.l. on 12 February. Ash was not observed on satellite imagery. [Note: AVO received no other reports of an ash plume and did not detect ash on satellite imagery.]

Source: Anchorage Volcanic Ash Advisory Center (VAAC)

20 October-26 October 2004 Cite this Report

On 26 October, AVO lowered the Concern Color Code at Shishaldin from Yellow to Green. Volcanic tremor at the volcano had remained at a relatively constant and low level for more than a month. No new satellite observations indicative of significant activity in the summit crater had been received by AVO, and there had been no recent reports of ash emissions or ash on the snow near the summit. The low-level seismic tremor that continued to be recorded at the volcano was considered to be representative of the background rate of activity at Shishaldin.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 September-21 September 2004 Cite this Report

Low-level seismic tremor continued to be recorded at Shishaldin during 10-17 September. This level of activity is similar to that observed over the past several months. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 July-3 August 2004 Cite this Report

Low-level seismic tremor continued at Shishaldin during 22-30 July as it had for several months. On 24 July an AVO field crew observed vigorous steaming at the summit and what may have been ash deposits on the volcano's upper slopes. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

7 July-13 July 2004 Cite this Report

Low-level seismic activity characterized by weak but continuous tremor continued at Shishaldin during 7-13 July. No volcanic activity was observed at the volcano during clear weather, but AVO reported that satellite data indicated the crater to be warmer than the surrounding ground surface. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

23 June-29 June 2004 Cite this Report

Seismic unrest continued at Shishaldin during 18-25 June, with weak tremor and occasional discrete low-frequency earthquakes occurring. A pilot reported seeing steam rise to low levels above Shishaldin's cone. Around that time, a possible weak thermal anomaly was visible on satellite imagery. Shishaldin remained at Concern Color Code Yellow.

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

26 May-1 June 2004 Cite this Report

Seismic unrest continued at Shishaldin during 21-28 May. It was characterized by weak seismic tremor and occasional discrete low-frequency earthquakes. Meteorological clouds obscured views of the volcano. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

19 May-25 May 2004 Cite this Report

During 14-21 May seismic unrest continued at Shishaldin, characterized by weak seismic tremor and small explosions. On 16 May, a pilot reported an ash plume that rose ~300 m above the volcano's summit. Satellite imagery from 17 May showed a vigorous plume emanating from the summit that may have contained small amounts of ash. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

12 May-18 May 2004 Cite this Report

During 7-14 May seismic unrest continued at Shishaldin, characterized by sequences of volcanic earthquakes, small explosions, and seismic tremor. A weak thermal anomaly observed at Shishaldin's summit on 11 May was similar to those detected occasionally since January 2004. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

5 May-11 May 2004 Cite this Report

Seismic unrest continued at Shishaldin during 30 April to 7 May. It was characterized by sequences of volcanic earthquakes and seismic tremor. The number of airwaves recorded by the seismic network diminished in comparison to the previous week, but weaker signals were recorded. Thermal anomalies at the summit were observed on satellite imagery under optimal viewing conditions. Retrospective analysis confirmed that these data, as well as similar signals observed in January 2004, were the first thermal anomalies observed at Shishaldin since August 2000. AVO saw no signs that an eruption was imminent. Shishaldin remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

28 April-4 May 2004 Cite this Report

AVO raised the Concern Color Code at Shishaldin from Green to Yellow on 3 May due to unusual seismic activity at Shishaldin during the previous week. Seismicity changed at the volcano from discrete earthquakes to more continuous ones. Tremor was observed for the first time since the most recent eruption ended in May 1999. Airwaves (acoustical waves traveling in air) accompanying earthquakes were recorded by the seismic network, suggesting that the source of seismicity had become more shallow. AVO reported that there were no indications that an eruption was imminent or even likely. Satellite data showed no significant increase in ground temperature at the volcano, nor had there been reports of increased steaming. However, AVO warned that activity at Shishaldin could increase rapidly and increased the frequency of their seismic-data analysis.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

22 May-28 May 2002 Cite this Report

During 17-24 March, the number of locatable low-frequency seismic events at Shishaldin greatly decreased in comparison to the previous week, returning to background levels. Shishaldin remained at Concern Color Code Green ("volcano is in quiet, "dormant" state").

Source: US Geological Survey Alaska Volcano Observatory (AVO)

15 May-21 May 2002 Cite this Report

During 10-17 May, the Alaska Volcano Observatory detected an increase in background seismicity at Shishaldin. There was an increase in the number of locatable shallow low-frequency earthquakes and several 2 to- 3-minute-long tremor-like signals that were inferred to be from a deep source. No thermal anomalies were visible on satellite imagery and there were no eyewitness reports of anomalous volcanic activity. Shishaldin remained at Concern Color Code Green ("volcano is in quiet, "dormant" state").

Source: US Geological Survey Alaska Volcano Observatory (AVO)

---

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
Agajedan | Sisquk | Chichaldinskoi | Shushaldinskaya | Sisaguk | Fernandez, Volcano de | Caroli (?) | Smoking Moses | Moses | Sissagjuk
Cones
Feature Name	Feature Type	Elevation	Latitude	Longitude
Olive, Mount	Cone

Basic Data Volcano Number Last Known Eruption Elevation Latitude Longitude 311360 2023 CE 2,857 m / 9,373 ft 54.756°N 163.97°W Morphology Volcano Landform Composite Volcano Types Stratovolcano Pyroclastic cone(s) Maar(s) Tuff cone(s) Rock Types Major Basalt / Picro-Basalt Andesite / Basaltic Andesite Minor Dacite Trachyte / Trachydacite Rhyolite Tectonic Setting Subduction zone Continental crust (> 25 km) Population Within 5 km Within 10 km Within 30 km Within 100 km 0 0 10 197

Geological Summary The symmetrical glacier-covered Shishaldin in the Aleutian Islands is the westernmost of three large stratovolcanoes in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." Constructed atop an older glacially dissected edifice, it is largely basaltic in composition. Remnants of an older edifice are exposed on the W and NE sides at 1,500-1,800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is covered by massive aa lava flows. Frequent explosive activity, primarily consisting of Strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century. A steam plume often rises from the summit crater. This volcano is located within the Aleutian Islands, a UNESCO Biosphere Reserve property. References The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Beget J E, Nye C J, Schaefer J R, Stelling P L, 2003. Preliminary volcano-hazard assessment for Shishaldin volcano, Alaska. Alaska Dept Nat Resour Div Geol Geophys Surv, Rep Invest, 2002-4: 1-28. Coats R R, 1950. Volcanic activity in the Aleutian Arc. U S Geol Surv Bull, 974-B: 35-47. Fournelle J H, 1988. The geology and petrology of Shishaldin volcano, Unimak Island, Aleutian arc, Alaska. Unpublished PhD thesis, John Hopkins Univ, 507 p. Green J, Short N M, 1971. Volcanic Landforms and Surface Features: a Photographic Atlas and Glossary. New York: Springer-Verlag, 519 p. 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. Myers J D, 1994. The Geology, Geochemistry and Petrology of the recent Magmatic Phase of the Central and Western Aleutian Arc. Unpublished manuscript, unpaginated. Nye C J, Keith T E C, Eichelberger J C, Miller T P, McNutt S R, Moran S, Schneider D J, Dehn J, Schaefer J R, 2002. The 1999 eruption of Shishaldin volcano, Alaska: monitoring a distant eruption. Bull Volcanol, 64: 507-519. Petersen T, McNutt S R, 2007. Seismo-acoustic signals associated with degassing explosions recorded at Shishaldin Volcano, Alaska, 2003-2004. Bull Volcanol, 69: 527-536. 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. Vergniolle S, Caplan-Auerbach C, 2006. Basaltic thermals and subplinian plumes: constraints from measurements at Shishaldin volcano, Alaska. Bull Volcanol, 68: 611-630.

Eruptive History

There is data available for 40 confirmed Holocene eruptive periods.

Deformation History

There is data available for 1 deformation periods. Expand each entry for additional details.

Emission History

There is data available for 1 emission periods. Expand each entry for additional details.

Photo Gallery

Despite its extensive glacial cover, Shishaldin volcano maintains its symmetrical profile because of frequent eruptions. Aa lava flows, erupted from summit and satellitic vents, spread over the NW flank, the location of more than 2 dozen pyroclastic cones. The dominantly basaltic volcano is the highest peak in the Aleutian Islands. The rugged, dissected Isanotski volcano rises to the east behind Shishaldin.

Copyrighted photo by Katia and Maurice Krafft, 1978. An almost constant steam plumes pours down the north flank of Shishaldin volcano, the highest in the Aleutian Islands. The symmetrical volcano is the most prominent landmark on Unimak Island and is referred to by the Aleut Indians as Sisquk, meaning "mountain which points the way when I am lost." A large monogenetic cinder cone field is found on the NW flank of the basaltic volcano. The two large lakes in the distance are within Fisher caldera, a low-lying volcanic structure to the SW.

Copyrighted photo by Katia and Maurice Krafft, 1978. The small summit crater of symmetrical Shishaldin volcano produces an almost constant steam plume. Strong winds in this 1978 view from the east also sweep streams of linear atmospheric clouds across the flanks of the volcano. The dominantly basaltic volcano is built atop an older volcano, remnants of which can be seen on the west and NE sides.

Copyrighted photo by Katia and Maurice Krafft, 1978. The effects of differential erosion are dramatically seen in this aerial view of two Alaskan volcanoes. Isanotski volcano in the foreground, sometimes referred to as "Ragged Jack," has been extensively dissected by glaciers that have excavated steep walls separated by narrow ridges. The symmetrical Shishaldin volcano in the background is sometimes referred to as the Mount Fuji of the Aleutians. In contrast to Isanotski, Shishaldin is one of Alaska's most active volcanoes. Frequent eruptions maintain the young, constructional profile of the volcano.

Copyrighted photo by Katia and Maurice Krafft, 1978. Three volcanoes are constructed along an E-W trend on the eastern half of Unimak Island. Roundtop in the foreground is glacially eroded and has Holocene pyroclastic flow deposits and a group of lava domes to the south. Isanotski is in the background and Shishaldin is in the midground.

Photo by Clayton and Marcia Brown, 1986 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys). Unimak Island has three volcanoes constructed along an E-W line. Shishaldin is in the foreground and is the highest of the three in this 1987 photo. Isanotski is to the right and Roundtop is in the far distance.

Photo by Clayton and Marcia Brown, 1987 (courtesy of John Reeder, Alaska Div. Geology & Geophysical Surveys). This view of the summit of Shishaldin shows its near- constant crater plume, with its high point on the south rim. Pogromni volcano, part of the Westdahl volcanic complex at the western end of Unimak Island, forms the peak in the distance.

Photo Clayton and Marcia Brown, 1987 (courtesy of John Reeder, Alaska Div. Geology & Geophysical Surveys). Shishaldin, located on central Unimak Island in the Aleutians, has a summit crater that emits a nearly continuous plume. It is the highest and one of the most active volcanoes of the Aleutian Islands. There have been frequent Strombolian eruptions, sometimes with lava flows, since the 18th century.

Photo by Chris Nye (Alaska Division of Geological & Geophysical Surveys, Alaska Volcano Observatory).

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

There are no samples for Shishaldin in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites

Alaska Volcano Observatory (Link to Shishaldin)	The Alaska Volcano Observatory (AVO) is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska's hazardous volcanoes, to predict and record eruptive activity, and to mitigate volcanic hazards to life and property.
Copernicus Browser	The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions.
MIROVA	Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.
MODVOLC Thermal Alerts	Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.
WOVOdat    Single Volcano View    Temporal Evolution of Unrest    Side by Side Volcanoes	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. GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments.
Volcanic Hazard Maps	The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter.
IRIS seismic stations/networks	Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of Shishaldin. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice.
UNAVCO GPS/GNSS stations	Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of Shishaldin. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player.
DECADE Data	The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO2 to the atmosphere, but installing CO2 monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.
Large Eruptions of Shishaldin	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).
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).