ALASKA VOLCANO OBSERVATORY STATUS REPORT
U.S. Geological Survey
Wednesday, December 28, 2016, 9:32 PM AKST (Thursday, December 29, 2016, 06:32 UTC)

BOGOSLOF VOLCANO (VNUM #311300)
53°55'38" N 168°2'4" W, Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Bogoslof volcano remains in a state of elevated unrest. Seismic data from neighboring islands detected an increase in volcanic tremor at Bogoslof beginning at 17:55 AKST today (02:55 Dec 29 UTC), with the largest burst occurring at 18:07 AKST (03:07 Dec 29 UTC). The tremor signal lasted for approximately 50 minutes, ending around 18:46 AKST (03:46 Dec 29 UTC). This type of seismic activity has accompanied each of the previous explosions at Bogoslof volcano since the eruption began last week, prompting AVO to issue a Volcano Activity Notice and Volcano Observatory Notice for Aviation. It is unknown if this event produced airborne ash. Continued analysis of data from the Worldwide Lightning Location Network shows no indication of lightning strikes associated with an ash cloud, and infrasound sensors from nearby islands did not detect signals associated with ash emissions. Regional high cloud cover to 35,000 ft asl, however, is obscuring satellite views of the surrounding area preventing confirmation of the presence or absence of an ash cloud. The volcanic seismicity has subsided, for the moment, and the status of the volcano remains at Aviation Color Code ORANGE and Alert Level WATCH.

AVO has no ground-based volcano monitoring equipment on Bogoslof volcano. We continue to monitor satellite images, data from distant seismic and infrasound instruments, and information from the Worldwide Lightning Location Network for indications of significant activity.

OTHER ALASKA VOLCANOES

Other Alaska volcanoes show no signs of significant unrest: http://www.avo.alaska.edu/activity/

AVO scientists conduct daily checks of earthquake activity at all seismically-monitored volcanoes, examine web camera and satellite images for evidence of airborne ash and elevated surface temperatures, and consult other monitoring data as needed.

For definitions of Aviation Color Codes and Volcano Alert Levels, see: http://www.avo.alaska.edu/color_codes.php

FOR MORE INFORMATION ON ALASKA VOLCANOES: http://www.avo.alaska.edu

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

Pavel Izbekov, Acting Coordinating Scientist, UAFGI
pavel@gi.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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