USGS Volcano Notice - DOI-USGS-AVO-2025-10-12T19:24:49+00:00

Lava continues to erupt in the summit crater of Great Sitkin Volcano. Small earthquakes and rockfalls associated with the eruption also continue. Cloudy weather blocked views of the volcano from webcams and satellites. 

A power outage at AVO's data-receive facility in Adak has caused data from the Great Sitkin monitoring network to be unavailable since 4:40 AM today (12 October 1640 UTC). Repair work at the facility is currently ongoing. 

The current lava eruption began in July 2021 and since then has filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.

Frequent small earthquakes and infrasound signals, possibly caused by gas bubbles bursting deep within the volcanic conduit, continue at a rate similar to what has been seen during the current period of unrest.  Cloudy weather blocked satellite and webcam views yesterday. This morning, clear webcam views show a gas plume from Shishaldin's summit and possible discoloration of the snow high on the volcano's north flank. This may be due to resuspended ash by high winds over the past day. 

Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite images to detect eruptions.