Alaska Volcano Observatory

Lava continues to slowly erupt within the summit crater at Great Sitkin Volcano. Satellite data on January 18 confirmed this by showing active steaming from the central region of the summit dome. Satellite data on January 22 shows that this area is largely snow-free, while the rest of the dome is covered in snow. Clouds obscured webcam images of the volcano with the exception of January 22. Seismic activity remains low, with only occasional small earthquakes and rockfalls detected. 

The current eruption of lava 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. Satellite imagery showed barely elevated surface temperatures on January 19, 21, and 23, likely related to the continued gas emissions at the summit and favorable atmospheric conditions. Web camera images, when clear, showed a plume of gas rising from the summit crater. Low-level seismic activity has persisted, with volcanic tremor and small earthquakes occurring frequently. 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 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, the Alaska Volcano Observatory uses nearby geophysical networks, regional infrasound and lighting data, and satellite data to monitor the volcano.