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ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, March 13, 2021, 11:38 AM AKST (Saturday, March 13, 2021, 20:38 UTC)
56°11'52" N 159°23'35" W,
Summit Elevation 8225 ft (2507 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Low-level eruptive activity continues at Veniaminof. Clear satellite views yesterday showed deposits from minor low-level ash emissions from the small cone in the summit caldera extending ~10 km (6.2 miles) southeast. Strongly elevated surface temperatures and a steam plume were also observed from the eruption of lava within the intracaldera glacier at a vent ~1 km (0.6 miles) east of the cone summit. Local seismic data was partially restored yesterday and elevated seismicity and tremor were observed. No explosions were detected in regional infrasound data. Although ash emissions have declined from earlier in the week, new ash deposits within the caldera over the past day demonstrate continued potential for minor ash emissions at altitudes below 10,000 ft asl. No ashfall has been reported in nearby communities.
Eruptive activity at Veniaminof usually consists of minor ash emissions, lava fountaining and lava flows from the small cone in the summit caldera. Ash emissions are typically confined to the summit crater, but larger events can result in ash fall in nearby communities and drifting airborne ash.
The partial restoration of local seismic data will help the Alaska Volcano Observatory to detect changes in unrest that may lead to a more significant explosive eruption. AVO combines seismic, infrasound, lightning, web camera, and satellite data for rapid detection of such events.
51°55'44" N 179°35'52" E,
Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
No volcanic activity was observed at Semisopochnoi over the past day in mostly cloudy satellite views. No activity was detected in regional infrasound data.
Semisopochnoi is monitored by satellite data, regional infrasound, and lightning detection instruments. 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
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Matthew Haney, Acting Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
David Fee, Coordinating Scientist, UAFGI
email@example.com (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.