ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Sunday, July 31, 2022, 12:14 PM AKDT (Sunday, July 31, 2022, 20:14 UTC)
Pavlof Volcano continues to erupt from the vent on the volcano’s east flank just below the summit. Elevated surface temperatures in the active vent and steam emissions were observed in partly cloudy satellite views of the volcano over the past day. Seismic tremor and numerous small explosions were detected in local seismic and infrasound data, as well as on regional stations. Webcam views were obscured by clouds, but these explosions were likely accompanied by minor ash emissions reaching less than 10,000 ft above sea level.
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. Clouds obscured all satellite and webcam views of the volcano. 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. Occasional small local earthquakes were detected over the past day. Clouds obscured all satellite and webcam views of the volcano. No explosions were detected.
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 may continue and could be difficult to detect, especially when thick cloud cover obscures the volcano.
Semisopochnoi is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Unrest continues at Cleveland. No significant seismicity was detected over the past day. Elevated surface temperatures were observed in otherwise cloudy satellite views.
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.
For definitions of Aviation Color Codes and Volcano Alert Levels, see: http://www.avo.alaska.edu/color_codes.php
SUBSCRIBE TO VOLCANO ALERT MESSAGES by email: http://volcanoes.usgs.gov/vns/
FOLLOW AVO ON FACEBOOK: https://facebook.com/alaska.avo
FOLLOW AVO ON TWITTER: https://twitter.com/alaska_avo
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.