Printer friendly version
ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Wednesday, March 10, 2021, 12:32 PM AKST (Wednesday, March 10, 2021, 21:32 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 imagery, web camera views, and local observations of the eruption yesterday showed continued ash emissions from the small cone in the summit caldera, in addition to the eruption of lava from a vent ~1 km (0.6 miles) east of the cone summit on the cone flank under the intracaldera glacier. Low-level plumes of volcanic ash have been observed at ~7,000–10,000 ft asl extending 200 km (124 miles) downwind, both to the northeast yesterday afternoon and to the southeast overnight into this morning. Explosions corresponding to this activity have been detected on regional geophysical networks. Even when extensive plumes are not visible, these low-level emissions are likely continuous within the caldera at altitudes below 10,000 ft asl. Strongly elevated surface temperatures have been observed in satellite imagery, consistent with lava effusion from the flank vent within the intracaldera glacier. Ash fall is mostly confined to the summit caldera but has been observed up to 20 km from the vent. No ashfall has been reported in nearby communities and updated guidance on modeled ash fall can be found at: https://www.avo.alaska.edu/activity/ash3d/ashfall.php?vid=ak301
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 local seismic data remains offline due to an outage of a satellite link at Port Heiden. However, the Alaska Volcano Observatory continues to monitor Veniaminof with satellite data and remote infrasound, seismic and lightning networks.
51°55'44" N 179°35'52" E,
Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
A small steam plume was observed at Semisopochnoi over the past day in partly 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
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
Dave Schneider, 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.