USGS Volcano Notice - DOI-USGS-AVO-2025-01-02T20:48:38+00:00

Lava continues to erupt slowly at Great Sitkin. A satellite image from last night shows hot ground at the summit from the ongoing eruption, and small earthquakes continue at a low rate. Webcam views of the volcano have been mostly clear over the past day and show no unusual activity. 

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.

Shallow earthquakes beneath the summit of Mount Spurr continue, at an increased rate today compared to the past few days. A flurry of earthquakes this morning included one with a magnitude of 2.9 at 5:39 AKST (14:39 UTC), which is among the largest seen in the current episode of unrest. Earthquake activity has quieted again over the last couple of hours. While notable, variation in the number and size 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. Clear satellite and webcam images from the past day showed no unusual surface activity.

AVO continues to 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.