ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, January 2, 2023, 1:05 PM AKST (Monday, January 2, 2023, 22:05 UTC)
A likely explosive event was detected in geophysical data over the past day, with elevated seismicity seen on local seismometers and an infrasound signal measured several minutes later on a regional infrasound array at Adak. The infrasound signal arrived at the array from the direction of Semisopochnoi. Otherwise, seismicity was low. Minor steam and gas emissions were observed in partly clear web camera views during the last 24 hours; however, clouds obscured satellite images and no ash plumes were observed.
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. Several local earthquakes were detected in seismic data during the last 24 hours. The two largest earthquakes occurred to the east of the volcano with magnitudes of 2.3 and 1.5. Satellite and web camera views were obscured by clouds.
Great Sitkin Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks.
No eruptive activity observed. Weakly elevated surface temperatures were observed in a satellite image over the past day. Otherwise, satellite images and web camera views were obscured by clouds. Occasional small low frequency seismic events were observed but declined in number over the last 24 hours.
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 continued over the past day, with several small local earthquakes detected. 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 noteworthy seismic activity was detected over the past day. Nothing significant observed in cloudy satellite images and web camera 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.
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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.