Alaska Volcano Observatory

Cloudy conditions for the past week prevented most satellite and webcam observations. Satellite data from September 22, however, showed minor continued growth of the eastern lava flow in the summit crater. Seismic activity remains low, with only occasional minor volcanic earthquakes and signals from small rockfalls related to growth of the lava flow. 

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, geodetic, and infrasound sensors, satellite data, and web cameras, and regional infrasound and lightning networks.

Volcanic activity remains slightly elevated. Stormy conditions obscured seismic and infrasound signals for parts of the week, but small earthquakes, ongoing tremor, and occasional infrasound signals could be seen during calmer conditions. While clouds obscured most satellite and webcam views, steam plumes were visible in web camera images during clear weather. Satellite data occasionally detected minor sulfur dioxide gas emissions. The frequency and magnitude of earthquakes, infrasound signals, and gas emissions all have declined over recent months.

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.