Alaska Volcano Observatory

Lava continues to erupt slowly at Great Sitkin, and small earthquakes associated with this ongoing eruption continue at a low rate. Satellite and web camera observations were obscured by clouds over the past day.

The current eruption of Great Sitkin Volcano began with a single explosive event in May 2021. The ongoing eruption of lava at the summit began shortly afterward, in July 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.

There has been an increase in the number shallow earthquakes located near the summit of Mount Spurr over the past day. The sequence lasted for about 14 hours before decreasing over the past several hours. While notable, variation in the numbers of earthquakes is common during periods of unrest at volcanoes and at this time does not suggest that eruptive activity is more likely in the near future. Satellite and web camera images showed no signs of activity at the surface.

AVO continues to closely monitor activity at Mount Spurr for signals that would indicate that the volcano is moving closer to an eruption. Based on previous eruptions, changes from current activity in the earthquakes, ground deformation, summit lake, and fumaroles would be expected if magma began 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.

The volcano is monitored using local seismic, infrasound, web camera, and GNSS stations along with regional infrasound, lightning networks and satellite data.