Alaska Volcano Observatory

Lava continues to erupt slowly within the summit crater at Great Sitkin Volcano. Minor lava dome growth and rockfalls continue along the east and south sides of the lava field. Satellite and webcam observations were limited due to cloud cover throughout the week, although rare clear views show moderately elevated surface temperatures and steaming from the active portion of the lava flow. Seismic activity remains low, with occasional small volcanic earthquakes and signals from minor rockfalls within the crater.

The current lava eruption began in July 2021 and has filled most of the summit crater and advanced into the 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.

Shishaldin Volcano continues to exhibit volcanic unrest. Seismic and infrasound activity remain elevated, as indicated by numerous small earthquakes, frequent infrasound signals, and continuous volcanic tremor recorded throughout the week. Clear webcam images show persistent steaming from the summit of the volcano and clear satellite imagery shows occasional weakly elevated surface temperatures at the summit. Elevated sulfur dioxide gas emissions were detected in satellite data on most days this week.

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