ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, February 18, 2017, 12:55 PM AKST (Saturday, February 18, 2017, 21:55 UTC)
53°55'38" N 168°2'4" W,
Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: RED
The eruption of Bogoslof volcano continues. After the explosion the morning of 17 February, a subsequent minor explosion was observed in seismic and infrasound data at around 15:46 AKST (00:46 UTC). The resulting volcanic cloud was observed in satellite views with cloud tops at around 25,000 ft asl.
The morning of 18 February, at around 4:50 AKST (13:50 UTC), an explosion occurred producing a cloud again. The explosion was detected by seismic, infrasound, lightning and satellite observations. This volcanic cloud traveled south-west at around 25,000 ft asl.
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.
52°49'20" N 169°56'42" W,
Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
No significant activity was observed in mostly cloudy views of the volcano by satellite and web camera over the past day. No significant volcanic activity has been detected in seismic or infrasound data over the past 24 hours. The presence of the recently emplaced lava dome within the summit crater may act to block the vent, resulting in reduced or restricted gas emissions which 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.
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/
FOLLOW AVO ON FACEBOOK: https://facebook.com/alaska.avo
FOLLOW AVO ON TWITTER: https://twitter.com/alaska.avo
Michelle Coombs, Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
Jeff Freymueller, Coordinating Scientist, UAFGI
email@example.com (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.