Printer friendly versionALASKA VOLCANO OBSERVATORY
Wednesday, February 22, 2006 3:35 PM AKST (035 UTC)
52°22'52"N 174°9'15"W , Summit Elevation 5030 ft (1533 m)
Current Level of Concern Color Code: YELLOW
Previous Level of Concern Color Code: GREEN
Beginning on January 17, the AVO seismic network detected a distinct, but brief increase in seismicity at Korovin Volcano on Atka Island. Similar periods of elevated seismicity occurred on January 18, 21 and again this morning. One event recorded at 06:35-06:46 AKST (15:35-15:46 UTC), January 22, was sustained for a period of 11 minutes. The elevated seismicity at Korovin indicates that the volcano may be entering a period of unrest and AVO is raising the level of concern color code for Korovin Volcano from Green to YELLOW.
The type of seismic activity we have observed may indicate that low-level volcanic activity is occurring or will soon occur. Clear satellite images yesterday and up until 06:00 AKST this morning however, do not show any unusual activity. Clouds obscure views of the volcano at this time. Previous eruptive activity at Korovin in 2005 was characterized by low-level ash and steam emissions (less than 10,000 feet above sea level).
AVO is monitoring the situation closely and will provide information should activity increase.
Korovin Volcano is a 1553 m high stratovolcano located on the northern part of Atka Island in the central Aleutian Islands, about 184 km (110 mi) east of Adak, 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 apart, that have been the sites of eruptive activity as recently as June, 1998. Korovin has erupted several times in the past 200 years, including 1907, 1951, 1953, 1954, 1973, 1976, 1986, 1987, 1996, and 1998, and 2005. All of these eruptions produced 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 4900 to 9200 m (16,000 to 30,000 feet) above sea level.
ABBREVIATED COLOR CODE KEY
(contact AVO for complete description):
GREEN volcano is dormant; normal seismicity and fumarolic activity occurring
YELLOW volcano is restless; eruption may occur
ORANGE volcano is in eruption or eruption may occur at any time
RED significant eruption is occurring or explosive eruption expected at any time
VOLCANO INFORMATION ON THE INTERNET: http://www.avo.alaska.edu
RECORDING ON THE STATUS OF ALASKA'S VOLCANOES (907) 786-7478
Chris Waythomas, Acting Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
Steve McNutt, Acting Coordinating Scientist, UAF-GI
email@example.com (907) 474-7131
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.