It was last active in but emits a constant plume of steam from a small summit crater. Shishaldin is the youngest of the eastern group of Unimak volcanoes which includes neighboring Isanotski and Roundtop volcanos. The Shishaldin cone is less than 10, years old and lies on a glacially eroded remnant of an ancient shield volcano. The entire cone above about ft m elevation is covered by snow and glacial ice. Despite the many violent eruptions, Shishaldin is one of the most symmetrical cone-shaped mountains on earth.
Shishaldin Volcano was designated as a National Natural Landmark in There are currently sites designated in 48 states, 3 territories, and the Commonwealth of Puerto Rico. Read more here and here.
Explore the shoreline of Shishaldin Volcano and Unimak Island here:. Shishaldin volcano, located near the center of Unimak Island in the eastern Aleutian Islands, is a spectacular symmetric cone with a base diameter of approximately 16 km 10 mi.
A m-wide ft funnel-shaped summit crater typically emits a steam plume and occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including over 24 confirmed eruptions since Most eruptions are relatively small, although the April-May event generated an ash column that reached 45, ft above sea level.
The Alaska Volcano Observatory continues to monitor Veniaminof with satellite data, remote infrasound, and lightning networks. On 14 March, lava and a possible new cone were visible in the summit crater using satellite imagery, accompanied by small explosion signals.
Strong thermal signatures due to the lava were also seen in Sentinel-2 satellite data and continued strongly through the month figure Seismic and infrasound data identified small explosions signals within the summit crater during March. Sentinel-2 thermal satellite imagery continued to show a weak hotspot in the crater summit through May figure 41 , which was also detected by the MIROVA system on two days. A daily report on 6 May reported a visible ash deposit extending a short distance SE from the summit, which had likely been present since 29 April.
AVO noted that the timing of the deposit corresponds to an increase in the summit crater diameter and depth, further supporting a possible small collapse. Small gas-and-steam emissions continued intermittently and were accompanied by weak tremors and occasional low-frequency earthquakes through May figure Minor amounts of sulfur dioxide were detected in the gas-and-steam emissions during 20 and 29 April, and 2, 16, and 28 May. The volcano continued to be monitored with local webcams, satellite data, and remote infrasound, seismic, and lightning networks.
Additionally, satellite images showed no new lava in the crater area, typical surface temperatures, and minor steaming.
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. AVO reported elevated seismicity at Shishaldin during 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 April. AVO reported elevated seismicity at Shishaldin during 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. AVO reported elevated seismicity at Shishaldin during 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 March.
AVO reported that seismicity at Shishaldin was characterized as near-continuous tremor during March and continuous tremor during 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. Weak but elevated seismicity was also recorded along with small explosion signals during March. Elevated surface temperatures, consistent with lava in the summit crater, were identified in satellite images during March. A small steam plume rising from the summit crater was visible in a webcam image on 17 March.
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 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.
AVO reported that seismic activity at Shishaldin remained above background levels during January. Elevated surface temperatures continued to be identified in satellite images, though became weak during January.
Infrasound data suggested that minor explosions were occurring at the summit during January. Small steam plumes from the summit were visible on 22, 23, and 26 January.
AVO reported that after almost a week of relatively quiet conditions at Shishaldin, during January seismicity began to climb and the temperature of the thermal anomaly slightly increased.
Activity intensified at on 19 January and by around the plume became more ash-rich. By around the ash plume rose to 6. Lava flows descended the NE and N flanks and generated lahars. By 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.
Minor amounts of ash fell in False Pass. Ash emissions had significantly declined by 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.
During 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. AVO summarized the 7 January eruptive activity at Shishaldin, characterizing the period of activity during as the most sustained explosive activity of the eruptive sequence so far.
Ash plumes drifted over km ENE, were ash rich during , and caused several flight cancellations and minor ashfall in Cold Bay. Elevated surface temperatures continued to be identified in satellite images during January, indicating lava effusion; seismicity decreased but remained above background levels. Satellite images acquired during January showed weak surface temperatures, indicated cooling lava; seismicity remained above background levels.
AVO reported that the eruption at Shishaldin continued during January. Seismicity was low during January and elevated surface temperatures identified in several satellite images indicated continuing lava effusion. Seismicity began increasing at on 3 January and within several hours a brief period of sustained ash emissions produced plumes that rose as high as 8. 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 km long.
During January seismicity was low but above background levels and elevated surface temperatures were visible in satellite images.
Seismicity increased at around on 7 January and was followed by observations of an ash plume drifting NE at an altitude of about 5. 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.
Volcanic lighting was detected in the cloud and volcanic infrasound signals were detected at regional stations. Seismcity significantly decreased around and remained low. AVO reported that the eruption at Shishaldin continued during December. Seismicity was elevated with weak explosions recorded by the network during 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 December confirmed a 1. 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.
AVO reported that seismicity at Shishaldin remained elevated during 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 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. Three lightning strokes were detected between and The explosion may have collapsed the summit spatter cone. Highly elevated surface temperatures were visible in satellite images during 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. AVO reported that elevated surface temperatures at Shishaldin were identified in satellite images during December consistent with lava effusion, and a pilot confirmed active lava flows on the flank. Continuous tremor was recorded by the seismic network during December.
Seismicity, including Strombolian explosion signals, continued to increase until 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. The eruption either slowed or paused during December as evidenced by decreased seismicity and slightly elevated surface temperatures in satellite data. Temperatures again increased and were slightly elevated during December, likely signifying renewed lava effusion. 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. 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.
AVO reported that increased seismicity and higher surface temperatures at Shishaldin during November indicated elevated eruptive activity. Seismicity abruptly dropped at on 20 November and remained low, heralding another pause in activity.
Tremor and surface temperatures remained low through 23 November. Seismicity again increased during 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 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 November. Strongly elevated surface temperatures were identified in multiple satellite images, and incandescence from the summit was occasionally visible in web camera images overnight. AVO reported that the eruption at Shishaldin continued at variable levels during November.
Seismicity increased during 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.
Strongly elevated surface temperatures and a steam plume drifting more than km SE were visible on 15 November. An incandescent lava flow on the NE flank was recorded in webcam images. Activity during 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 November.
Periods of high-amplitude tremor during 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.
Seismic tremor was low during 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 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.
Activity decreased during 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. AVO reported that by 28 October two stalled lava flows extended as far as 1.
Activity paused during 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 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. On 3 November lava overflowed the summit crater and traveled at least m down the NW flank and 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. 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 October overflowed the N crater rim.
A m-long lava flow on the N flank melted snow and caused a lahar which traveled 2. 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. Low-level eruptive activity continued during October. Seismicity remained elevated, with periods of high-amplitude tremor. Small explosions were recorded during October.
A central spatter cone was visible. Spatter deposits on the snow at the upper flanks was evident, and tephra deposits extended about 2.
The lahar on the NW flank branched extensively at lower elevations and was at least 5 km long. Weather clouds had mostly prevented views of the crater during October; elevated surface temperatures were detected during 13 and October. A steam plume was visible in webcam images on 19 October. 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. AVO reported that during 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 webcam possibly recorded a steam emission on 16 September. 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. AVO reported that during 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. AVO reported that during August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were visible in infrared satellite images.
AVO reported that during August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were visible in satellite images. 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. Elevated surface temperatures were observed in multiple satellite images during 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 July. AVO reported that weak tremor continued to be recorded at Shishaldin during 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.
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. 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.
AVO reported that seismic and infrasound data from Shishaldin continued to indicate elevated activity during December. Robust steaming was recorded by a webcam during December; ice and poor weather conditions prevented views during the rest of the period. Steam emissions visible in satellite and webcam images during 5 and December were rising hundreds of feet above the summit crater. 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. 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. AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during November, indicating that low-level eruptive activity confined to the summit crater continued.
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. AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during October, indicating that low-level eruptive activity confined to the summit crater continued.
AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 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. 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 October.
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. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 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. AVO reported that seismicity at Shishaldin was only slightly above background levels during September. No activity was observed in satellite or webcam images during clear periods. Cloud cover often prevented satellite and webcam observations; elevated surface temperatures were periodically detected in satellite images. 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.
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 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.
AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 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. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 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.
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 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. AVO reported that seismicity at Shishaldin continued to be elevated over background levels July, indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover prevented satellite and webcam observations. AVO reported that seismicity at Shishaldin continued to be elevated over background levels July indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were detected in satellite images during July.
Although cloud cover often prevented visual observations, webcam images showed periodic steaming, and ash at the summit during July.
Elevated surface temperatures at the summit were detected in satellite images on 3 and 7 July. AVO reported that seismicity at Shishaldin continued to be elevated over background levels 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.
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 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.
AVO reported that seismicity at Shishaldin continued to be elevated over background levels June indicating that low-level eruptive activity confined to the summit crater likely continued. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during June, indicating that low-level eruptive activity confined to the summit crater likely continued. 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 May. AVO reported that seismicity at Shishaldin continued to be elevated over background levels May indicating that low-level eruptive activity confined to the summit crater likely continued. AVO reported that seismicity at Shishaldin continued to be elevated over background levels 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. Periodically, elevated temperatures in the crater were detected and steaming was recorded by the webcam, although cloud cover sometimes prevented views of the volcano.
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. AVO reported that seismicity at Shishaldin continued to be elevated over background levels April, indicating that low-level eruptive activity confined to the summit crater likely continued.
Slight steaming was recorded by the webcam on 26 April and elevated temperatures were detected in satellite images during April. AVO reported that seismicity at Shishaldin continued to be elevated over background levels April indicating that low-level eruptive activity confined to the summit crater likely continued. On 16 April the webcam periodically recorded a white steam plume rising about 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.
AVO reported that seismicity at Shishaldin continued to be elevated over background levels during April. They interpreted those data as indicating that low-level eruptive activity confined to the summit crater likely continued.
AVO reported that seismicity at Shishaldin continued to be elevated over background levels during April indicating that low-level eruptive activity confined to the summit crater likely continued. Highly elevated surface temperatures in the crater were detected during April, suggesting the presence of lava within the crater. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 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 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 km S.
Nothing significant was observed in mostly cloudy satellite and web camera images; slight steaming at the summit was visible during March. Minor steaming from the summit was observed in webcam images on 11 March. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during March. Elevated surface temperatures were sometimes detected in satellite images.
Low-level eruptive activity confined to the summit crater likely continued. 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. AVO reported that seismicity at Shishaldin continued to be elevated over background levels during February. Cloud cover often prevented webcam and satellite-image views of the volcano.
Weakly elevated surface temperatures were detected in satellite images during 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. AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during February. Elevated surface temperatures were observed in satellite images on most days, and minor steam emissions were recorded by the web cam during February.
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 February low-level ash emissions drifted WSW.
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 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 January showed a small steam plume, indicating that the current activity was mostly contained in the deep summit crater. AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 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. 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.
AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 31 December-6 January.
Minor steam emissions were occasionally recorded by the webcam. AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during December. AVO reported that seismicity at Shishaldin continued to be elevated during December. Occasional steam emissions were recorded by the web camera. A low-level lava eruption was likely still occurring within the summit crater of the volcano. Thermal anomalies were often detected in satellite images during periods of clear weather.
Webcam images on 9 December showed minor steam emissions. 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.
AVO reported that intermittent volcanic tremor at Shishaldin continued to be detected during November. Elevated crater temperatures were detected in satellite images during periods of clear weather; thermal anomalies were reported during 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. AVO reported that seismicity at Shishaldin remained elevated during November. Elevated crater temperatures were detected in satellite images during periods of clear weather. Satellite and webcam views showed nothing unusual; temperatures at the summit were elevated on 5 November.
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. AVO reported that partly cloudy satellite images and mostly cloudy webcam views showed nothing unusual at Shishaldin during 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.
AVO reported that, although cloud cover often obscured views of Shishaldin during 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. AVO reported that, although cloud cover often obscured views of Shishaldin during 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 and October. AVO reported that seismicity at Shishaldin indicated that a low-level eruption likely continued during October. Strongly elevated surface temperatures at the summit were periodically detected in satellite images; cloud cover sometimes obscured satellite and webcam observations. AVO reported that, although cloud cover sometimes obscured views of Shishaldin during 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. AVO reported that low-level seismicity and eruptive activity continued from Shishaldin during September. Observations were frequently restricted due to cloudy conditions, although elevated temperatures were observed on 15 September in one satellite image.
When weather conditions were favorable, satellite images detected elevated surface temperatures. Observations were restricted on September due to cloudy conditions. 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. AVO reported that during August low-level eruptive activity continued at Shishaldin volcano.
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