ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, September 12, 2020, 11:39 AM AKDT (Saturday, September 12, 2020, 19:39 UTC)

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

A few small local earthquakes were detected over the past day. No signs of unrest were observed in satellite and web camera images.

Great Sitkin volcano 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: ADVISORY
Current Aviation Color Code: YELLOW

Several earthquakes were detected over the past day. Seismic data transmission has been temporarily interrupted due to network connectivity issues. Uncertain when these will be resolved. Nothing noteworthy observed in satellite imagery over the past day and AVO has received no reports of unrest or unusual activity at Semisopochnoi from passing pilots.

Semisopochnoi is monitored by local seismic sensors, satellite data, and regional infrasound and lightning detection instruments. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.

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

David Fee, Coordinating Scientist, UAFGI
dfee1@alaska.edu (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.

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