USGS Volcano Notice - DOI-USGS-AVO-2026-05-20T18:30:15+00:00

Small earthquakes associated with lava dome growth and rockfalls were detected in seismic data. Other satellite and webcam images of the volcano were obscured by clouds.

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.

An gas plume of sulfur dioxide was detected drifting to the north from Shishaldin Volcano. Seimsic and infrasound sensors continue to detect frequent small events. Satellite and webcam views of the volcano were obscured by clouds.

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. 

A few small earthquakes were detected with regional seismic stations over the last day. A small sulfur dioxide plume was seen in satellite data over the volcano. Other satellite images were obscured by clouds.

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.