ALASKA VOLCANO OBSERVATORY STATUS REPORT
U.S. Geological Survey
Friday, February 3, 2017, 8:23 PM AKST (Saturday, February 4, 2017, 05:23 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

Seismic tremor associated with the eruption of Bogoslof volcano that began at 1:41 UTC on February 4 (16:41, February 3 AKST) has significantly decreased and it is likely that ash emissions have ended or are greatly diminished below the detection limit. The eruption produced a small volcanic ash plume that was observed in visible wavelength satellite data beginning at 02:00 UTC for about an hour moving towards the north over the Bering Sea at an altitude of less than 25,000 ft above sea level. The cloud is no longer observable in visible satellite data after sunset and it is not easily distinguishable in thermal infrared data that can observe clouds at night. Several earthquakes have occurred at Bogoslof following the end of this period of seismic tremor and ash emissions, indicating continued unrest.

Bogoslof volcano remains at a heightened state of unrest and in an unpredictable condition. Additional explosions producing high-altitude volcanic clouds could occur at any time. Low-level explosive activity that is below our ability to detect in our data sources may be occurring. These low-level explosions could pose a hazard in the immediate vicinity of the volcano.

The Aviation Color Code remains at ORANGE and the Alert Level remains at WATCH.

Status of the ash cloud forecast can be found at the National Weather Service Alaska Aviation Weather Unit website at http://aawu.arh.noaa.gov/

OTHER ALASKA VOLCANOES

Information on all Alaska volcanoes is available at : http://www.avo.alaska.edu.

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

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

Jeff Freymueller, Coordinating Scientist, UAFGI
jfreymueller@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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