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ALASKA VOLCANO OBSERVATORY
Friday, January 9, 2004 10:20 AM AST (19:20 UTC)
ANNOUNCING SEISMIC MONITORING OF OKMOK CALDERA
53o24'N, 168o 10'W summit elevation 1073 m (3521 ft)
Since summer 2002, AVO has been receiving seismic data from 12 stations on
Okmok Caldera, which occupies most of northeastern Umnak Island in the
Aleutians. We now have an understanding of background seismicity. As of
today, Okmok Caldera is added to our list of seismically monitored
volcanoes in Alaska.
Okmok caldera is a large central volcanic complex with a nested caldera.
Several major eruptions and a number of minor events have occurred in Okmok
caldera in historic time. The most recent eruption occurred in early 1997.
Seismic activity is monitored in real time at 25 volcanoes in Alaska.
Satellite images of all Alaskan volcanoes are analyzed daily for evidence
of ash plumes and elevated surface temperatures. Some volcanoes may
currently display anomalous behavior but are not considered to be at a
dangerous level of unrest.
Wrangell, Spurr, Redoubt, Iliamna, Augustine, Snowy, Griggs, Katmai,
Novarupta, Trident, Mageik, Martin, Aniakchak, Veniaminof, Pavlof, Dutton,
Isanotski, Shishaldin, Fisher, Westdahl, Akutan, Makushin, Okmok, Great
Sitkin, and Kanaga volcanoes are in color code GREEN. All are at or near
normal levels of background seismicity. AVO did not detect ash plumes or
significant elevated surface temperatures in the vicinity of any volcano.
ABBREVIATED COLOR CODE KEY (contact AVO for complete description):
GREEN volcano is dormant; normal seismicity and fumarolic activity
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
Tom Murray, Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
John Eichelberger, Coordinating Scientist, UAF-GI
email@example.com (907) 474-5530
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.