USGS Volcano Notice - DOI-USGS-AVO-2023-08-17T11:14:00-08:00

Seismicity was generally low at Cleveland volcano over the past day, but a few earthquakes were detected at the volcano. No activity was observed in cloudy satellite and web camera views of the volcano.

Episodes of lava effusion and explosions can occur without advance warning. Explosions from Mount Cleveland are normally short-duration and only present a hazard to aviation in the immediate vicinity of the volcano. Larger explosions that present a more widespread hazard to aviation are possible but are less likely and occur less frequently.

Cleveland volcano is currently monitored by a local seismic network, infrasound sensors, and web cameras. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite observations to detect eruptions. Based on past events, explosive eruptions of Cleveland may occur with little or no warning. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, web camera, lightning, and satellite data.

Slow eruption of lava continues within the summit crater of Great Sitkin Volcano. Earthquake activity remains slightly elevated over the past day.  No significant activity was observed in cloudy webcam and satellite views of the volcano.

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

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

Low levels of seismicity and a small plume of steam and minor amounts of ash characterized activity at Shishaldin Volcano over the past day. Steam and ash emissions were visible in clear web camera images obtained yesterday, but the plume was small, and any ash present likely fell out on the volcano's flanks. Elevated surface temperatures were observed in satellite images over the past day, indicating hot material on the upper parts of the volcano. Clouds have obscured web camera views today.

Shishaldin has had seven periods of elevated eruptive activity resulting in significant ash emissions and mass flows of volcanic debris on the flanks of the volcano. The ongoing eruptive period started on July 12, and it is unknown how long this eruptive episode will last. However, previous eruptions of Shishaldin Volcano have lasted weeks to months with repeated cycles of activity similar to those seen over the last month.

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

Seismic activity near Trident Volcano remained slightly elevated over the past day. No activity was observed in clear to cloudy satellite images and web camera views.

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 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.   AVO issued an Information Statement on July 25 providing a more detailed update on the volcanic unrest at Trident Volcano and the broader Katmai volcanic cluster (https://www.avo.alaska.edu/news.php?id=1595).

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