ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, November 6, 2021, 11:45 AM AKDT (Saturday, November 6, 2021, 19:45 UTC)

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

Eruptive activity continues at the north crater of Mount Cerberus. Explosions and tremor were detected in seismic and infrasound data over the past day. Low-level ash emissions were observed in web camera data during periods of clear weather. High meteorological clouds obscured the volcano and no ash emissions were observed in satellite data rising above the meteorological cloud deck, which had an estimated cloud top altitude of 10,000 to 20,000 ft asl. The seismic and infrasound amplitudes of the explosions were typical of those observed during this eruption, suggesting that ash emissions were likely rising 5,000 to 10,000 ft asl.

Small eruptions producing minor ash deposits within the vicinity of the active north crater of Mount Cerberus and ash clouds usually under 10,000 feet above sea level have characterized the recent activity, which shows no signs of abating. Small explosions may continue to occur and could be difficult to detect, especially during poor weather conditions.

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


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

Lava effusion may be continuing. Barely elevated surface temperatures were observed in satellite during brief periods of partly cloudy conditions. Seismicity over the past day was at very low levels and no explosive activity has been observed in seismic or infrasound data over the past day. Satellite and web camera images were mostly obscured by clouds over the past day.

There is no indication of how long lava effusion will continue during the current eruption, and it is possible that explosive activity could occur with little or no warning.

Great Sitkin is monitored by local seismic and infrasound sensors, satellite data, web cameras, and remote infrasound and lightning networks.


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

Low-level eruptive activity continues. Seismicity remains elevated, with several small explosions and discontinuous tremor being observed in geophysical data over the past day. Satellite and web camera images were obscured by clouds, but very small ash clouds were likely generated by the explosive events.

Small explosions accompanied by low-level ash emissions could happen at any time, and are typically a hazard in the immediate vicinity of the summit. The level of unrest at Pavlof can change quickly and the progression to more significant eruptive activity can occur with little or no warning.

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


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, UAF, 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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