USGS Volcano Notice - DOI-USGS-AVO-2026-06-06T18:45:42+00:00

Slow eruption of lava continues. Minor seismicity detected over the past day. Typical slightly elevated surface temperatures were observed in satellite data. 

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.

Occasional earthquakes continued over the past day. On the afternoon of June 5, three pilot reports were received reporting volcanic ash emissions in the vicinity of Mount Veniaminof, located to the northeast of Kupreanof. Several photos from a pilot were forwarded to AVO via the FAA and NWS which showed the source of the activity to be the fumarole field on Kupreanof. The photos showed vigorous steam degassing, which is typical for the volcano, and dark discolored snow and ice near the fumarole field. It is common for vigorous degassing to dislodge small rock particles and deposit them nearby, giving the impression of volcanic ash emissions. Satellite observations from the afternoon of  June 5 showed sulfur dioxide emissions near the volcano, which has been typical during this recent stage of unrest. These observations confirm that unrest continues, but they do not represent an increase in volcanic activity. 

There is no real-time geophysical monitoring network at Mount Kupreanof. The closest functioning seismometers are approximately 17 miles (27 km) to the east 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. 

Unrest continues. Minor seismic activity and infrasound were detected at the volcano.  A pilot report of a steam plume extending for 75 nautical miles was received this morning. This is longer than usual, but is likely due to favorable atmospheric conditions and not increased volcanic gas emissions. Satellite data from yesterday afternoon showed typical sulfur dioxide emissions from the volcano. No other activity was observed in satellite data.

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.