ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Tuesday, January 7, 2020, 2:20 PM AKST (Tuesday, January 7, 2020, 23:20 UTC)

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

An eruption at Shishaldin that began at 5:00 a.m. AKST (14:00 UTC) is ongoing. A sharp but brief increase in seismicity was detected this morning followed by observations of a volcanic cloud drifting to the northeast at about 19000 ft asl. Seismicity waned for a few hours, followed by a subsequent increase. During this increase in intensity, the volcanic cloud increased in altitude to about 25000 ft asl and appeared to increase in ash content, prompting a change in Aviation Color Code to RED and Alert Level to WARNING. Satellite views show strongly elevated surface temperatures and web camera views show incandescence. Volcanic lighting was detected in the cloud and volcanic infrasound was detected at regional stations. Seismicity has decreased significantly since 12:00 AKST (21:00 UTC) and the ash emissions appear to be decreasing. Trace fallout of ash is expected in the communities to the northeast, potentially up to Sand Point.

Shishaldin is monitored by local seismic and infrasound sensors, satellite data, web cameras, a telemetered geodetic network, and distant infrasound and lightning networks.

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

No eruptive activity at Cleveland Volcano has been detected in local seismic or infrasound data over the past day. No unusual activity observed in satellite and web camera views over the past day.

Episodes of lava effusion and explosions can occur without advance warning. Explosions from Cleveland are normally short duration and only present a hazard to aviation in the immediate vicinity of the volcano. Larger explosions that present a more widespread hazard to aviation are possible, but are less likely and occur less frequently.

Cleveland volcano is monitored by only two seismic stations, 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.

PAVLOF VOLCANO (VNUM #312030)
55°25'2" N 161°53'37" W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

No eruptive activity or emissions from the summit have been observed. Elevated seismicity continues, but has not changed significantly over the past several days.

The level of unrest at Pavlof can change quickly and the progression to eruptive activity can occur with little or no warning. We continue to monitor Pavlof closely and will provide any new information about the status of the volcano when or if it becomes available.

Pavlof is monitored by local seismic and infrasound sensors, satellite data, web cameras, and distant infrasound and lightning networks.


SEMISOPOCHNOI VOLCANO (VNUM #311060)
51°55'44" N 179°35'52" E, Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Nothing significant was observed in satellite views of Semisopochnoi over the past day. Nothing noteworthy detected in seismic data or other geophysical monitoring data.

Semisopochnoi is monitored by local seismic sensors, satellite data and distant lightning networks. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.

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, 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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