ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, January 4, 2020, 11:33 AM AKST (Saturday, January 4, 2020, 20:33 UTC)

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

Low-level eruptive activity is likely continuing at Shishaldin Volcano. Following yesterdays eruption, seismic levels declined abruptly and have remained low over the past day. Elevated surface temperatures were observed in several partly cloudy satellite views of the volcano after yesterdays activity, but since then, no new satellite data were available until a few hours ago. Recent satellite observations indicate that nothing noteworthy is occurring at the volcano and there are no signs of ash emission. High resolution WorldView satellite data show the upper part of the volcano is mantled with ash. Lahars (volcanic mudflows) are evident on the upper part of the edifice, particularly on the southwest flank. Lava flows are visible on the upper northwest and northeast flanks and extend 1-2 km (0.6-1.2 miles) from the summit crater vent. No other signs of unrest have been observed since yesterdays brief eruption. Web camera views of the volcano remain obscured by clouds and snow.

Although the present level of seismicity is low, it remains possible for unrest to escalate at any time and additional ash producing eruptive events may occur.

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 significant activity was observed in mostly cloudy satellite data and web camera images over the past 24 hours.

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.

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 satellite and lightning sensors. 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:

Matt Haney, Acting Scientist-in-Charge, USGS
mhaney@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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