USGS Volcano Notice - DOI-USGS-AVO-2026-05-12T20:06:22+00:00

Slow lava effusion continues within the Great Sitkin summit crater. Over the past day, seismic data recorded small earthquakes and rockfalls from the growing lava dome. Satellite and webcam views of the volcano were obscured by clouds.

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

Seismic activity and volcanic gas (sulfur dioxide) emissions increased over the past few months and now continue at elevated levels at Mount Kupreanof. This activity is likely caused by a magmatic intrusion beneath the volcano. AVO increased the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY in response to this sustained volcanic unrest today. Data do not suggest an eruption is imminent and further signs of increased unrest would be expected prior to eruption. Views of the volcano were obscured by clouds today, but elevated seismicity was detected on regional monitoring networks.

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 persists at Shishaldin Volcano, with seismic and infrasound activity remaining elevated over the past day. Sulfur dioxide emissions were observed in satellite imagery. Webcam and other satellite imagery 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.