USGS Volcano Notice - DOI-USGS-AVO-2025-03-31T20:09:44+00:00

Unrest continues at Mount Spurr volcano. Seismicity remains elevated with numerous small, shallow volcanic earthquakes detected beneath the volcano over the past day. No activity detected in satellite data or web-camera data.

AVO continues monitoring activity at Mount Spurr for signals indicating that the volcano is moving closer to an eruption. Based on previous eruptions, changes from current activity in the earthquakes, ground deformation, summit lake conditions, and fumarolic activity would be expected if magma began to move closer to the surface. Therefore, if an eruption occurred, it would be preceded by additional signals allowing warning.

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

Lava continues to erupt slowly in the summit crater of Great Sitkin Volcano, and small earthquakes continue at a low rate. Weakly elevated surface temperatures observed in satellite data. Minor steam emissions observed in web camera imagery.

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.

Strong northwesterly winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes have picked up loose volcanic ash erupted during the 1912 Novarupta-Katmai eruption and carried it to the southeast. The National Weather Service has issued a SIGMET for this low-level event and suggests that the maximum cloud height is 4,000 ft above sea level.

This phenomenon is not the result of recent volcanic activity and occurs during times of high winds and dry snow-free conditions in the Katmai area and other young volcanic areas of Alaska. No eruption is in progress.

Resuspended volcanic ash should be considered hazardous and could be damaging to aircraft and health. For more information on volcanic ash and human health, visit the following website: http://volcanoes.usgs.gov/ash/. Official warnings about these ash resuspension events are issued by the National Weather Service: https://www.weather.gov/afc/. Forecasts of airborne ash hazard to aircraft: https://www.weather.gov/aawu/. Volcanic Ash Advisories: https://www.weather.gov/vaac/. Forecasts of ash fall: http://www.weather.gov/afc. Air quality hazards and guidance from Alaska Department of Environmental Conservation, Division of Air Quality: http://dec.alaska.gov/Applications/Air/airtoolsweb/Advisories/Index