ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Tuesday, February 7, 2017, 12:38 PM AKST (Tuesday, February 7, 2017, 21:38 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

The eruption of Bogoslof volcano continues. Possible weakly elevated surface temperatures were observed in one satellite image over the past 24 hours, probably related to hot eruptive deposits from explosive activity on February 4 UTC (February 3 AKST). No significant activity has been detected in seismic or infrasound data over the past 24 hours.

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. Some previous explosions have been preceded by an increase in earthquake activity that allowed for short-term forecasts of imminent significant explosive activity. Although we are able to detect energetic explosive activity in real-time, there is typically a lag of tens of minutes until we can characterize the magnitude of the event and the altitude of the volcanic cloud. 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. When such low-level activity occurs, it is considered to be consistent with Aviation Color Code ORANGE and Volcano Alert Level WATCH.

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

CLEVELAND VOLCANO (VNUM #311240)
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Weakly elevated surface temperatures were observed at the summit of Cleveland in several satellite images over the past day. This is consistent with the presence of a lava dome that began extruding in the summit crater in late January. Web camera views have been obscured by clouds. No significant activity observed in seismic or pressure sensor data during the past 24 hours. The presence of an active lava dome within the summit crater may lead to explosive activity with little to no warning.

Cleveland volcano is not monitored with a real-time seismic network and this inhibits AVO's ability to detect unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of satellite, infrasound, lightning data and local observations. AVO is monitoring the unrest at Cleveland volcano as closely as possible and will release additional information if or when it becomes available.

TAKAWANGHA VOLCANO (VNUM #311090)
51°52'1" N 178°1'37" W, Summit Elevation 4754 ft (1449 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

The energetic earthquake swarm on Tanaga Island that began on January 23, 2017 has declined significantly. No activity has been detected in cloudy satellite views over the past day.

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

Jessica Larsen, Acting Coordinating Scientist, UAFGI
jflarsen@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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