Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, April 21, 2006 2:00 PM AKDT (2200 UTC)
59°21'48"N 153°26'W , Summit Elevation 4134 ft (1260 m)
Current Level of Concern Color Code: ORANGE
Eruptive activity continues at Augustine Volcano. Seismicity, rates of rockfall signals, and visual observations from overflights earlier this week indicate lava effusion is continuing.
On Monday and Tuesday, a flurry of avalanche signals larger than those seen in the past few weeks occurred. Based on aerial observations on Wednesday, it appears that an active rockfall and avalanche chute has developed near the margin of the new lava flow/dome complex in the northwest summit area. A blanket of ash related to recent rockfall events in this area was visible on the southwest flank of the volcano. Additional rockfalls are expected in this sector as long as the current activity continues.
Small, dilute ash clouds produced by these sudden, occasional rockfalls and avalanches may still occur, but are unlikely to extend beyond Augustine Island. Brief energetic explosions of ash are still possible.
AVO is monitoring Augustine closely and the observatory remains staffed 24/7.
56°11'44"N 159°23'18"W , Summit Elevation 8225 ft (2507 m)
Current Level of Concern Color Code: YELLOW
Seismicity remains low. A steam plume possibly containing minor amounts of ash was visible earlier in the week. Production of short-lived, very small-volume steam and ash bursts from the intracaldera cone has been typical of this volcano intermittently over the past few years. There are no indications that a larger eruption is imminent. Ash clouds and fallout from these events are not likely to extend beyond the caldera rim, but could pose a hazard to people and low-flying aircraft in the vicinity of the active cone.
OTHER ALASKA VOLCANOES
Seismic activity is monitored in real time at 30 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, Snowy, Griggs, Katmai, Novarupta, Trident, Mageik, Martin, Peulik, Ukinrek Maars, Aniakchak, Pavlof, Dutton, Isanotski, Shishaldin, Fisher, Westdahl, Akutan, Makushin, Okmok, Korovin, Great Sitkin, Kanaga, Tanaga, and Gareloi 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 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
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.