Alaska Volcano Observatory

Lava continues to erupt at a slow rate in the summit crater of Great Sitkin. The last satellite radar imagery was from October 23, showing continued eruption of lava. A clear webcam view on October 28 showed steaming from the active eruption site.  Intermittent small volcanic earthquakes continue, though the rate has slowed over the past month.

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 Alaska Volcano Observatory (AVO) monitors Great Sitkin using seismic, infrasound, and satellite data. 

Unrest continues at Mount Spurr. About 100 small, shallow earthquakes beneath the summit were detected during the past week. A few episodes of weak volcanic tremor, indicative of possible deep fluid movement, were also observed over the past week. We saw no unusual activity in satellite or web camera images during clear weather windows. A high-resolution satellite image from October 27 showed no changes at the summit crater. The crater lake is still mostly covered in ice.  

AVO is closely monitoring Mount Spurr for signs of increased unrest. We would expect changes in the earthquakes, ground deformation, summit lake, and fumaroles if magma began to move closer to the surface. Thus, if an eruption were to occur, it would be preceded by additional signals that would allow advance warning.