ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, December 31, 2022, 12:59 PM AKST (Saturday, December 31, 2022, 21:59 UTC)
Seismic tremor and explosions were detected in geophysical data over the past day. Satellite and web camera views were obscured by clouds. No plumes were observed above the meteorological cloud deck (≤ 15,000 ft above sea level), so any ash emissions that may be occuring in association with these geophysical signals are low-level.
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 and more ash-producing events could occur again with little warning.
Semisopochnoi volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
Lava likely continued to erupt in the summit crater of Great Sitkin Volcano over the past day. A few small local earthquakes were detected in seismic data. Satellite and web camera views were obscured by clouds over the past day.
Great Sitkin Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
No eruptive explosions or lava flow activity were detected in seismic, infrasound, satellite, or web camera data over the past day. Low-level seismic tremor and small earthquakes were detected in geophysical data. However, satellite and web camera views were obscured by clouds 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.
The ongoing earthquake swarm near Takawangha volcano is continuing over the past day. This activity may be due to the movement of magma beneath the volcano. No other signs of unrest were observed in cloudy satellite views.
No significant seismic activity was detected over the past day. A steam plume was observed in partly cloudy web camera imagery. No activity was observed in cloudy satellite views.
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 three local 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
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Michelle Coombs, Scientist-in-Charge, USGS, firstname.lastname@example.org, (907) 786-7497
David Fee, Coordinating Scientist, UAFGI email@example.com (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.