USGS Volcano Notice - DOI-USGS-AVO-2024-10-16T20:26:06+00:00

Lava continues to erupt slowly at Great Sitkin Volcano. Ongoing activity is adding to a thick lava flow that fills most of the summit crater with minor advancement of the northern part of the eastern lobe. Small earthquakes associated with the ongoing lava eruption continue. Nothing unusual was observed in cloudy satellite and web camera imagery.  

A single explosive event occurred in May 2021 and was followed by the ongoing eruption of lava that began in July 2021. No explosive events have occurred since May 2021. Local seismic and infrasound sensors and web cameras are used to monitor Great Sitkin along with regional infrasound and lightning networks and satellite data.

There has been a gradual increase in volcanic unrest at Mount Spurr over the past several months. GNSS receivers have detected sustained upward and outward ground deformation since March 2024. An increase in seismic activity has also been noted since April. Other indications of elevated elevated activity include the development of a small lake in the summit crater in early summer of 2024. Because this is a notable departure from the normal background seismicity of the volcano, AVO raised the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY. However, there are no indications that an eruption is imminent. Often this type of seismicity and ground deformation will decline without producing an eruption.

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 proceeded by additional signals that would allow advance warning.

Local seismic, infrasound, web cameras, and GNSS stations are used to monitor Mount Spurr along with regional infrasound, lightning networks and satellite data.