ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, October 1, 2022, 12:01 PM AKDT (Saturday, October 1, 2022, 20:01 UTC)
Low-level eruptive activity continues from a vent just below the summit of Pavlof Volcano, on its east flank. Strongly elevated surface temperatures were seen in satellite views, and a weak steam plume was visible in webcam views. Seismic tremor continued over the past day.
Small explosions associated with the current eruption could happen at any time and may be accompanied by small ash plumes within the immediate vicinity of the volcano. The level of unrest at Pavlof Volcano can change quickly and the progression to more significant eruptive activity can occur with little or no warning.
Pavlof Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Low-level eruption of lava likely continues at Great Sitkin Volcano. Seismicity was low, and satellite and webcam views were obscured by clouds.
The terrain is steep near the terminus of the current eruption's lava flows, and blocks of lava could detach without warning and form small rock avalanches in these valleys. These avalanches may liberate ash and gas and could travel several hundred meters beyond the lava flows; they would be hazardous to anyone in those areas.
Great Sitkin Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Seismicity was low over the past day at Semisopochnoi volcano, with one episode of weak tremor detected. No ash emissions or other activity were observed in cloudy satellite and webcam views.
Small eruptions producing minor ash deposits within the vicinity of the active north crater of Mount Cerberus and ash clouds usually under 10,000 ft (3 km) above sea level have characterized the recent activity. Small explosions and associated ash emissions could resume and may be difficult to detect during periods of high winds and/or when thick cloud cover obscures the volcano. Ash emissions over the past several years of activity have typically reached altitudes of less than 10,000 ft (3 km) above mean sea level.
Semisopochnoi volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
An ongoing outage is affecting the seismic network at Mount Cleveland. No activity was seen in satellite data over the past day.
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.
When the seismic network is operational, Mount Cleveland is monitored by only two seismic stations, which restricts AVO's ability to precisely locate earthquakes and detect precursory unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, lightning, and satellite data.
Small earthquakes beneath Trident Volcano continued to be detected. No activity was observed in satellite or webcam views. The Aviation Color Code and the Volcano Alert level were raised to YELLOW/ADVISORY on September 29.
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.
OTHER ALASKA VOLCANOES
Information on all Alaska volcanoes is available at: http://www.avo.alaska.edu.
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Michelle Coombs, Scientist-in-Charge, USGS, email@example.com, (907) 786-7497
David Fee, Coordinating Scientist, UAFGI, firstname.lastname@example.org, (907) 378-5460
The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
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