USGS Volcano Notice - DOI-USGS-AVO-2023-12-16T08:53:24-09:00

Low-level unrest continues at Shishaldin Volcano. Seismic activity remains slightly elevated, with small, low-frequency earthquakes and tremor observed over the past day. A few clear satellite views showed nothing of note. A few clear web camera views of the volcano yesterday morning showed minor steam emissions from the summit crater. 

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. Satellite views of the volcano were obscured by clouds. A few clear web camera views of Great Sitkin from Adak Island obtained yesterday morning showed nothing of note.

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 were detected under Trident and neighboring volcanoes over the past day. No volcanic activity was observed in satellite views of the volcano over the past day. 

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.