USGS Volcano Notice - DOI-USGS-AVO-2021-12-11T12:22:49-09:00

ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Sunday, December 12, 2021, 11:47 AM AKST (Sunday, December 12, 2021, 20:47 UTC)

GREAT SITKIN VOLCANO (VNUM #311120)
52°4'35" N 176°6'39" W, Summit Elevation 5709 ft (1740 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Seismicity is low but remains above background levels. Satellite and web camera views of the volcano were mostly cloudy over the past day, and no volcanic activity was observed. Lava effusion probably continues at a slow rate, and it is possible that explosive activity could occur with little or no warning.

Great Sitkin is monitored by local seismic and infrasound sensors, satellite data, web cameras, and remote infrasound and lightning networks.


PAVLOF VOLCANO (VNUM #312030)
55°25'2" N 161°53'37" W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Volcanic unrest continues at Pavlof Volcano. Seismicity remained elevated over the past day, but no explosion signals were detected. Elevated surface temperatures were observed in satellite views. No ash emissions were seen in satellite or webcam views.

Small explosions accompanied by low-level ash emissions could happen at any time, and are typically a hazard in the immediate vicinity of the summit. 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 remote infrasound and lightning networks.


SEMISOPOCHNOI VOLCANO (VNUM #311060)
51°55'44" N 179°35'52" E, Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Low-level eruptive activity and elevated seismicity continue at Semisopochnoi volcano. Small explosions from North Cerberus volcano were recorded by seismic and infrasound sensors, and ash emissions were seen in mostly cloudy webcam views. Satellite views were obscured by clouds.

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 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 remote infrasound and lightning networks.


DAVIDOF VOLCANO (VNUM #311040)
51°57'15" N 178°19'34" E, Summit Elevation 1076 ft (328 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Small earthquakes continue in the seismic swarm near Davidof volcano, although at a reduced rate and amplitude. Satellite views of the volcano were cloudy over the past day, and no volcanic activity was observed.

There is no real-time seismic monitoring network at Davidof volcano. The closest seismometers are approximately 15 km to the east of the volcano on Little Sitkin Island. Davidof is also monitored by satellite data and remote infrasound and lightning networks.

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/

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CONTACT INFORMATION:

Michelle Coombs, Scientist-in-Charge, USGS, mcoombs@usgs.gov (907) 786-7497

Janet Schaefer, Acting Coordinating Scientist, DGGS janet.schaefer@alaska.gov (907) 322-4085

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.