ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, August 6, 2022, 11:49 AM AKDT (Saturday, August 6, 2022, 19:49 UTC)
Pavlof Volcano continues to erupt from the vent on the volcano’s east flank just below the summit. Seismic tremor and small explosions were detected in local seismic and infrasound data, as well as on regional stations. No ash emissions were observed in webcam images during periods of clear viewing conditions, but these explosions were likely accompanied by minor ash emissions reaching less than 10,000 ft above sea level. Ash emissions during this current eruption have been too small to be observed in satellite data, but elevated surface temperatures at the active vent were observed in satellite images 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 can change quickly and the progression to more significant eruptive activity can occur with little or no warning.
Pavlof 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. Seismicity remains low with occasional small local earthquakes over the past day. Typical elevated surface temperatures related to lava effusion were observed in satellite images over the past day. Webcam views during periods of clear weather showed no change in activity. It is possible that new explosive activity could occur with little or no warning.
Great Sitkin is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Low-level unrest continues. No earthquakes or explosions were detected over the past day. Steam emissions from the north crater of Mount Cerberus were observed in web camera images of the volcano during periods of clear weather and in a high-resolution satellite image from yesterday afternoon.
There have been no observations of ash emissions from the north crater of Mount Cerberus since mid-June 2022, although steam emissions continue. 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 is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Unrest continues at Cleveland. Local seismic data flow has been restored, and one small local earthquake was detected over the past day. Typical elevated surface temperatures were observed in satellite images over the past day. No explosive activity was detected on local or regional networks.
Episodes of lava effusion and explosions can occur without advance warning. Explosions from 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 operational, Cleveland volcano 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.
OTHER ALASKA VOLCANOES
Information on all Alaska volcanoes is available at: http://www.avo.alaska.edu.
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Dave Schneider, Acting Scientist-in-Charge, USGS email@example.com (907) 786-7497
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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.