Alaska Volcano Observatory

Lava continues to slowly erupt within the summit crater at Great Sitkin Volcano. High-resolution satellite images show that lava flows have advanced slightly to the south, and rockfalls from these flows are ongoing. Weakly elevated surface temperatures were observed in satellite views on Saturday. For most of the week, clouds obscured the volcano, but occasional clear views showed no unusual activity. Seismic activity remains low, with only occasional small earthquakes and rockfalls detected.

The current lava eruption began in July 2021 and 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. 

Signs of volcanic unrest at Shishaldin Volcano continued this week. Web camera images, when clear, showed a plume of gas rising from the summit crater. Low-level seismic activity has persisted, with small earthquakes occurring daily. Infrasound signals, likely caused by gas bubbles bursting deep within the volcanic vent, were also detected throughout the week when the conditions were not too windy. At this time, there is no evidence of lava at or near the surface.

Shishaldin Volcano is monitored by local seismic and infrasound sensors, web cameras, and a telemetered geodetic network. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite data to monitor the volcano.