No significant local seismicity was observed at Great Sitkin Volcano during the last 24 hours—events recorded on the seismic network there were principally from earthquake swarms at nearby Tanaga Volcano and Takawangha volcano. Elevated surface temperatures were seen in satellite images. Webcam views were cloudy.

Great Sitkin Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.

Earthquake activity beneath Tanaga Volcano and nearby Takawangha volcano continued at a high rate over the past 24 hours, with more than 100 events per hour at times. Most of these earthquakes are shallower than about 10 km (6 miles) below sea level, and the largest have magnitudes up to about 4. No eruptive activity was seen in relatively clear satellite views of the volcano.

Tanaga Volcano is monitored with a local seismic and infrasound network, regional infrasound and lightning detection networks, and satellite data.

Earthquake activity beneath Takawangha volcano and nearby Tanaga Volcano continued at a high rate over the past 24 hours, with more than 100 events per hour at times. Most of these earthquakes are shallower than about 10 km (6 miles) below sea level, and the largest have magnitudes up to about 4. No eruptive activity was seen in relatively clear satellite views of the volcano.

Takawangha volcano is monitored by local seismic and infrasound sensors, satellite data, and regional infrasound and lightning networks.

Small, shallow earthquakes continued to occur at a rate of several per hour over the past day at Aniakchak volcano. No eruptive activity was observed in mostly clear satellite images.

The current period of seismic unrest began in October 2022. Increases in seismic activity have been detected previously at other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and surface deformation to precede any future eruption, if one were to occur. 

AVO monitors Aniakchak with a local network, which currently consists of two functional seismometers, as well as satellite remote sensing data and regional infrasound and lightning networks.

Occasional small earthquakes in the vicinity of Trident Volcano continued to occur during the past 24 hours. No activity was seen in mostly clear webcam views and satellite imagery.

The current period of seismic unrest began on August 24, 2022. Increases in seismic activity have been detected previously at Trident Volcano and other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and surface deformation to precede any future eruption, if one were to occur. 

AVO monitors Trident Volcano with a local network of seismometers, a webcam, remote sensing data, and regional infrasound and lightning networks.

No significant local seismicity was observed at Semisopochnoi volcano during the last 24 hours—events recorded on the seismic network there were principally from earthquake swarms at nearby Tanaga Volcano and Takawangha volcano. A steam plume from the north cone of Mount Young was seen in relatively clear webcam and satellite views.

Small eruptions producing minor ash deposits within the vicinity of the active north crater of Mount Young and ash clouds usually under 10,000 ft (3 km) above sea level have characterized the recent periods of activity. Additional ash-producing events could occur again with little warning. 

Semisopochnoi volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.