ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Thursday, January 18, 2018, 3:27 PM AKST (Friday, January 19, 2018, 00:27 UTC)

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

Unrest continues at Cleveland volcano. No activity was observed in mostly clear satellite views over the past day. Nothing significant noted in seismic or infrasound data during the last 24 hours.

SHISHALDIN VOLCANO (VNUM #311360)
54°45'19" N 163°58'16" W, Summit Elevation 9373 ft (2857 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Low-level unrest continues at Shishaldin volcano. Over the last 24 hours, seismicity has continued above background levels. Nothing significant was observed in clear satellite data.

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

The Color Code/Alert Level for Great Sitkin was lowered to GREEN/NORMAL earlier today based on a decrease in earthquake activity over the past 2 months to near background levels. In addition, no significant activity has been observed in satellite data during this time period and no steam plumes have been reported.

The decline over the past 2 months in the number of earthquakes suggests an intrusion of magma beneath Great Sitkin, which caused elevated seismicity during late 2016 and most of 2017, has stalled and the volcano is returning to a period of background seismicity. Future intrusions at Great Sitkin should lead to an increase in earthquakes prior to any eruptive activity.

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

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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