This is a mid-infrared satellite image of Atka Island and surroundings captured at 13:23 UTC Feb 21 2025 (4:23 AM AKST). Coast outlines are in yellow. The various shades of gray correspond to the temperature of objects in the scene, with the scale at the bottom in degrees Celsius. Clouds and land are darker gray (cooler) than the ocean surface. The summit lake at Korovin Volcano is visible as a tiny spot of lighter gray on the northern side of Atka Island. Lakes, like the ocean, typically differ a bit in temperature from the land surface and are thus visible in mid-infrared images.
Volcano(es): Atka volcanic complex
Photographer: Schneider, David
URL: avo.alaska.edu/image/view/196366
Credit: Image courtesy of AVO/USGS.
Use Restriction: Please cite the photographer and the Alaska Volcano Observatory / U.S. Geological Survey when using this image.
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Atka volcanic complex 2025
On February 20, 2025, AVO raised the color code/alert level at Atka to ORANGE/WATCH, stating:
"A single, small explosive event was detected in local seismic and infrasound data at 4:26 UTC (7:26 pm AKST) at the Atka volcanic complex. As a result, the Aviation Color Code and Alert Level has been changed to ORANGE/WATCH. The explosive event was short in duration (less than 10 seconds), and it is likely that a small amount of volcanic ash was erupted during this event. A meteorological cloud deck at an altitude of 8,000 to 10,000 ft above sea level obscured direct satellite observations, but no ash emissions were observed above the clouds. There have been no further explosive events observed and no noticeable change in seismic activity."
On February 21, 2025, AVO lowered the color code/alert level to YELLOW/ADVISORY, stating: "There has been no further activity detected at the Aka volcanic complex since the small explosive event from 4:26 UTC on February 21 (7:26 pm on 2/20/25 AKST), and seismicity remains low. Thus, the Aviation Color Code and Alert Level are being reduced to YELLOW/ADVISORY.
"Further analysis of geophysical data confirms the source of the explosion as the summit lake region of Korovin Volcano and satellite data from last evening show no evidence of hot material at the surface. Our interpretation is that this was a steam-driven explosion, caused by overpressure of the subsurface cap beneath the lake. This type of singular explosion is common at Korovin Volcano. Minor amounts of ash were likely erupted in the immediate vicinity of the vent but have not been confirmed. Additional explosions are possible in the near future, but unlikely."
On March 3, 2025, AVO lowered the color code/alert level back to GREEN/NORMAL, stating: "There has been no further explosive activity detected at the Atka volcanic complex since the small explosive event at 4:26 UTC on February 21 (7:26 pm on 2/20/25 AKST). Since then, seismicity has remained low. Thus, the Aviation Color Code and Alert Level are being reduced to GREEN/NORMAL."