USGS Volcano Notice - DOI-USGS-AVO-2026-09-09T18:25:36+00:00

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Minor earthquakes were detected in the past day. Steaming and elevated surface temperatures at the summit dome were observed in clear webcam and satellite views of the volcano.

The current eruption began in July 2021. 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.

Unrest continues at Shishaldin Volcano, with minor seismic activity detected in the past day. Clear webcam views of the volcano showed the typical gas plume emanating from the summit of the volcano. The SO2 gas plume was also detected 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. 

Seismic activity at Kupreanof Volcano over the past day was very low. Weak steaming from fumaroles on the flank of the volcano was seen in clear webcam views. Because of the sharp drop in seismicity to very low levels over the past month, and the decrease in SO2 gas emissions, the volcano's Aviation Color Code and Volcano Alert Level were lowered to UNASSIGNED yesterday afternoon. The volcano was not lowered to GREEN and NORMAL because of insufficient coverage by ground-based monitoring data.

A new temporary monitoring station was installed recently near Mount Kupreanof and is providing seismic data, infrasound data, gas measurements, and web camera images on an intermittent basis. This is by design to conserve battery power, but the frequency of data acquisition can be increased if activity warrants. The closest functioning seismometers that provide continuous data 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.