USGS Volcano Notice - DOI-USGS-AVO-2026-07-19T20:21:36+00:00

Minor earthquakes were detected over the past day, likely associated with rockfall on the growing dome. New satellite and webcam images show minor steaming from the active lava dome but no major changes from other recent views.

The current eruption began in July 2021 and, since then, lava flows have 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, webcams, and regional infrasound and lightning networks.

Typical elevated temperatures were seen in clear overnight satellite images form the Korovin Volcano crater lake. Minor seismic activity was also seen. Both observations are typical for the Atka volcanic complex and no unusual unrest has been detected following the July 16 explosion. 

The Atka volcanic complex includes several vents, including Korovin Volcano, Mount Kliuchef and Sarichef Volcano. Korovin has been the site of most historical eruptions that typically produce minor amounts of ash and occasional but small lava flows. The Atka volcanic complex is monitored by local seismic and infrasound sensors and webcam, satellite data, and regional lightning detection instruments.

Low-level unrest continues with seismic at low-levels. Clouds obscured satellite images.

While a new temporary monitoring station was installed in the last week near Mount Kupreanof, data are not yet available in real-time. The closest functioning seismometers are approximately 10 miles (16 km) to the northeast of the volcano as part of the Mount Veniaminof network. Mount Kupreanof is also monitored by satellite data, remote infrasound and lightning networks, and visual observations from pilots and mariners passing by the volcano.

Minor seismic signals were detected at the volcano. A sulfur dioxide gas plume was observed drifting east from the volcano in satellite data. Cloudy conditions obscured other satellite and webcam observations. 

Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lightning data, and satellite images to detect eruptions.