USGS Volcano Notice - DOI-USGS-AVO-2023-12-20T11:39:59-09:00

Low-level unrest continues at Shishaldin Volcano. Seismic activity remains slightly elevated, with small, low-frequency earthquakes and tremor observed over the past day. No activity was observed in cloudy satellite images, and steaming was observed in one clear webcam image.

Thirteen significant explosive events have occurred at Shishaldin from July 12 through October 3, 2023. These events have been preceded by increases in seismicity in the hours to days before they occur. It is unknown how long this period of ongoing activity will last. However, previous eruptions of Shishaldin Volcano have lasted weeks to months with repeated cycles of eruptive activity like those seen since July.

Local seismic and infrasound sensors, web cameras, and a geodetic network monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite images to detect eruptions.

Slow eruption of lava in the summit crater of Great Sitkin Volcano continues. Seismic activity was low over the past day. No activity was observed in cloudy satellite and web camera views of the volcano.

The current lava flow began erupting in July 2021. No explosive events have occurred since a single event in May 2021.

Local seismic and infrasound sensors, web cameras, regional infrasound and lightning networks, and satellite data are used to monitor the volcano.

Small, shallow earthquakes continued under Trident and neighboring volcanoes over the past day. In addition, deeper (greater than 20 km or 12 miles) volcanic earthquakes and seismic tremor were also observed. No volcanic activity was observed in satellite imagery. 

The current period of seismic unrest began in August 2022. Increases in seismic activity have been detected previously at Trident Volcano and other similar volcanoes and did not result in eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and ground movement, to precede any future eruption if one were to occur.   

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

Small earthquakes continued beneath Kanaga Volcano over the past day. Overall, the rate of seismicity has significantly declined since the explosion event on December 18 AKST (Dec. 19 UTC). The summit has been obscured by clouds, but satellite views of the lower flanks following the explosion showed a possible debris flow extending 1.5 km (0.9 miles) northwest from the summit crater rim.

The recent unrest indicates a possibility for sudden explosions of ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop. Kanaga Volcano is monitored by local seismic and infrasound sensors, regional infrasound and lightning networks, and satellite data.