ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, December 4, 2020, 11:29 AM AKST (Friday, December 4, 2020, 20:29 UTC)
Note that Daily Updates will cease while there are no volcanoes in Alaska at elevated alert levels. A weekly update will continue to be issued each Friday.
KOROVIN VOLCANO (VNUM #311161)
52°22'54" N 174°9'55" W, Summit Elevation 5030 ft (1533 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
The Aviation Color Code and Alert Level was decreased to GREEN/NORMAL on December 3, 2020. Unrest that began in late October 2020 has subsided. Seismic activity is at background levels and satellite observations show no signs of activity. Steaming is not unusual at Korovin and meteorological conditions can enhance the visibility of these emissions.
Korovin is monitored by local seismic and infrasound sensors, satellite data, regional lightning detection instruments, and reports from local observers.
Korovin Volcano is a 1553-m-high (5030 ft) stratovolcano located on the northern part of Atka Island in the central Aleutian Islands, about 21 km (13 mi) north of the community of Atka, 538 km (350 mi) west of Dutch Harbor, and 1760 km (1100 mi) southwest of Anchorage. The volcano has two distinct summit vents about 0.6 km (2000 ft) apart, that have been the sites of eruptive activity in historical time. The most recently active of the vents maintains a small, roiling, lake that occasionally produces energetic steam emissions. Thermal springs and fumaroles located on and near the volcano indicate an active hydrothermal system. Korovin has erupted several times in the past 200 years, including 1973, 1987, and 1998, and has likely had small ash emissions as recently as 2005. Typical recent Korovin eruptions produce minor amounts of ash and occasional but small lava flows. Reports of the height of the ash plume produced by the 1998 eruption ranged from 4,900 to 10,600 m (16,000 to 35,000 feet) above sea level.
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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Matt 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.