ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, January 15, 2021, 1:16 PM AKST (Friday, January 15, 2021, 22:16 UTC)

No eruptive activity or significant unrest has been detected at volcanoes in Alaska this week.

Monitoring of Alaskan volcanoes

The Alaska Volcano Observatory monitors daily all volcanoes in Alaska through a combination of local seismic networks, regional infrasound detectors, global lightning networks, satellite imagery, and web cameras. Volcanoes assigned aviation color code GREEN and volcano alert level NORMAL are monitored by a local seismic network capable of locating small earthquakes with reliable data transmission. Unassigned volcanoes are monitored by regional seismic and infrasound networks that can detect more significant activity, as well as satellite images.


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

The Shishaldin network has suffered several outages affecting GPS, seismic, and infrasound stations. Due to the impaired local monitoring stations, the Alaska Volcano Observatory changed the Aviation Color Code and the Volcano Alert Level UNASSIGNED/UNASSIGNED earlier today.

The Alaska Volcano Observatory continues to monitor Shishaldin with satellite data, remote infrasound, and lightning networks.

Shishaldin volcano, located near the center of Unimak Island in the eastern Aleutian Islands, is a spectacular symmetric cone with a base diameter of approximately 16 km (10 mi). A 200-m-wide (660 ft) funnel-shaped summit crater typically emits a steam plume and occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including over 24 confirmed eruptions since 1775. Most eruptions are relatively small, although the April-May 1999 event generated an ash column that reached 45,000 ft above sea level.

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

Data from the Veniaminof seismic network have not been received since December 8, 2020 due in part to an outage of a satellite link to Port Heiden. Repair efforts are planned, however, due to the absence of local seismic monitoring, the Alaska Volcano Observatory changed the Aviation Color Code and the Volcano Alert Level UNASSIGNED/UNASSIGNED earlier today.

The Alaska Volcano Observatory continues to monitor Veniaminof with satellite data, remote infrasound, and lightning networks.

Mount Veniaminof volcano is an andesitic stratovolcano with an ice-filled 10-km diameter summit caldera located on the Alaska Peninsula, 775 km (480 mi) southwest of Anchorage and 35 km (22 mi) north of Perryville. Veniaminof is one of the largest (~300 cubic km; 77 cubic mi) and most active volcanic centers in the Aleutian Arc and has erupted at least 14 times in the past 200 years. Recent eruptions in 1993-95, 2005, 2013, and 2018 all occurred at the intracaldera cone and lasted for several months. These eruptions produced lava spattering and fountaining, minor emissions of ash and gas, and small lava flows into intracaldera icefield. Minor ash-producing explosions occurred nearly annually between 2002 and 2010. Previous historical eruptions have produced ash plumes that reached 15,000 to 20,000 ft above sea level (1939, 1956, and 2018) and ash fallout that blanketed areas within about 40 km (25 mi) of the volcano (1939, 2018).

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/

FOLLOW AVO ON FACEBOOK: https://facebook.com/alaska.avo

FOLLOW AVO ON TWITTER: https://twitter.com/alaska_avo

CONTACT INFORMATION:

Matt Haney, Acting Scientist-in-Charge, USGS
mhaney@usgs.gov (907) 786-7497

Taryn Lopez, Acting Coordinating Scientist, UAF
tmlopez@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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