USGS Volcano Notice - DOI-USGS-AVO-2025-08-02T19:15:49+00:00

Low-level unrest continues at Mount Spurr. Seismic activity was low over the past day. Typical minor steaming was observed in sporadic clear views of the summit of Mount Spurr in satellite and webcam imagery. Carbon dioxide gas emissions from Crater Peak were detected by a gas monitoring instrument on the crater rim. 

Fluctuations in unrest are common at volcanoes and eruptive activity remains possible, but unlikely. Should unrest escalate towards an eruption, we expect to observe increases in seismic activity, gas emissions, surface deformation, and surface heating.

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

Lava continues to erupt in the summit crater of Great Sitkin Volcano. Low-level seismicity continues with occasional small earthquakes and rockfall signals detected. Clouds obscured all satellite and webcam views.

The current lava eruption began in July 2021 and has filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.