USGS Volcano Notice - DOI-USGS-AVO-2025-10-13T19:58:06+00:00

Lava continues to erupt in the summit crater of Great Sitkin Volcano. 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 mostly unavailable since early yesterday morning (October 12). Data came back briefly yesterday evening, and showed that small earthquakes and rockfall signals continue. 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. Yesterday, clear webcam views showed a plume from Shishaldin's summit drifting north; it was also reported by several pilots. The plume was dark at times, and we cannot rule out the possibility that it contained small amounts of ash. However, the color may have been due to lighting conditions and the presence of volcanic gas. Clear satellite images overnight showed no elevated surface temperatures at the summit, which would be expected if new magma had reached the surface. Today, webcam views of the volcano are cloudy. 

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.