Alaska Volcano Observatory

Activity at Great Sitkin Volcano has remained unchanged over the past week, with lava continuing to erupt slowly in the summit crater. Intermittent, small volcanic earthquakes persist. A small outgassing plume from the summit vent was seen a few times in webcam and satellite images, although most views during the week were obscured by clouds.

Since the May 2021 explosion, there have been no other explosions at Great Sitkin Volcano. The lava eruption that began in July 2021 is ongoing. It has filled most of the summit crater and advanced into valleys below. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks. 
 

Ongoing shallow earthquake activity continues at Mount Spurr Volcano, although at a lower rate than last week. To date, most of the earthquakes during this period of unrest have had magnitudes less than 1, including those detected this week. Ground deformation measured by a local network of Global Navigation Satellite System (GNSS) instruments shows slow, steady ground movement upward and outward since March 2024. An intrusion of magma beneath the volcano is the leading interpretation of the deformation data and the elevated seismicity. Occasional clear views of the volcano in satellite and web-camera images showed no unusual activity.

AVO continues to closely monitor activity at Mount Spurr for signals that would indicate that the volcano is moving closer to an eruption using local seismic, infrasound, web camera, and GNSS stations along with regional infrasound, lightning networks and satellite data. Based on previous eruptions, additional changes in earthquakes, ground deformation, the summit lake, and fumaroles would be expected if magma begins to move closer to the surface. Therefore, it is very likely that if an eruption were to occur it would be preceded by additional signals that would allow advance warning.