ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, December 24, 2018, 12:12 PM AKST (Monday, December 24, 2018, 21:12 UTC)

VENIAMINOF VOLCANO (VNUM #312070)
56°11'52" N 159°23'35" W, Summit Elevation 8225 ft (2507 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Seismic tremor increased at around 13:00 UTC on 12-23-2018. Robust steam emissions were observed in web camera views coincident with strongly elevated surface temperatures observed in satellite views. No ash signal was detected in these emissions. Acoustic signals were detected at the infrasound array at Sand Point. Lava fountaining was observed in web camera views through most of the evening with activity waning over the night. Seismic tremor as has since declined.

Veniaminof volcano is monitored with a local real-time seismic network, which will typically allow AVO to detect changes in unrest that may lead to a more significant explosive eruption. AVO combines seismic, infrasound, lightning, and satellite data for rapid detection of such events.



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

No unusual activity was observed in satellite views over the past day. No other activity was observed over the past day.

Cleveland volcano is monitored by only one seismic station, which restricts AVO's ability to detect precursory unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, lightning, and satellite data. The web camera, one seismic station, and the local infrasound array are offline due to a equipment failure on September 23rd. This hampers efforts to rapidly detect explosive activity; however, Cleveland remains monitored with a single seismic station and regional instruments.

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

Low-level unrest continues at Great Sitkin volcano. Numerous small earthquakes associated with the ongoing unrest continue to be recorded on the local seismic network. No eruptive activity was observed in cloudy satellite views of the volcano over the past day. No explosive activity was detected on a regional infrasound array on Adak Island.

Great Sitkin volcano is monitored with a local real-time seismic network, which will typically allow AVO to detect changes in unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption would be accomplished using a combination of seismic, infrasound, lightning, and satellite data.

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


David Fee, Acting Coordinating Scientist, UAFGI
dfee1@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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