Printer friendly versionALASKA VOLCANO OBSERVATORY
Wednesday, October 5, 2005 2:15 PM AKDT (2215 UTC)
51.885°N 178.1458°W, Summit Elevation 5925 ft (1806 m)
Current Level of Concern Color Code: GREEN
The Alaska Volcano Observatory (AVO) has detected a small increase in earthquake activity beneath Tanaga Volcano. The increased earthquake activity began late on October 1 and continues. The number of located events has ranged from 68 to 15 each day. This is in contrast to the low rate of less than one earthquake per month recorded since the seismic network was installed in 2003. Swarms of earthquakes such as this are common at volcanoes such as Tanaga and the size and depth of these events do not suggest that eruptive activity is imminent. Satellite data show nothing unusual. The color code for Tanaga remains at Green.
The earthquakes are centered roughly two km northeast of the summit of Tanaga Volcano and range in depth between 10 and 20 km below sea level. The largest event had a magnitude of 1.7 and most range in magnitude between 0.5 and 1.5. AVO continues to monitor the volcano closely using seismic and satellite data.
Tanaga is a remote 1806 m high (5,925 ft) high stratovolcano located roughly 105 km (63 miles) west of Adak in the Andreanof Islands. The last known eruption of Tanaga occurred in 1914 and earlier eruptions were reported in 1763-1770, 1791, and 1829.
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
Tom Murray, 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.