Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, August 11, 2006 11:15 AM AKDT (1915 UTC)
56°11'44" N159°23'18" W, Summit Elevation 8225 ft (2507 m)
Current Level of Concern Color Code: YELLOW
Seismicity at Veniaminof remains low. Satellite and web camera views during rare clear periods showed minor low-level steaming and no signs of unusual activity.
Intermittent, short-lived, very small-volume steam and ash bursts from the intracaldera cone have been common over the past few years. Ash from these events is not likely to extend beyond the caldera rim. There are no indications that a larger eruption is imminent.
59°21'48" N153°26' W, Summit Elevation 4134 ft (1260 m)
Current Level of Concern Color Code: GREEN
Based on the low level of activity at Augustine Volcano, AVO lowered the Level of Concern Color Code from YELLOW to GREEN on Wednesday, August 9, 2006.
Seismic data and observations made by AVO geologists working on the volcano indicate that activity has decreased to background levels. Visual observations and satellite data show that there have been no detectable changes at the summit over the last few months.
Despite the cessation of lava dome growth, the new dome and lava flows are still unstable, and small rock falls and avalanches may occur for several months, especially on the north flank of the volcano. The steep ends of the lava flows are also places where rock fall activity may continue. These areas are still considered hazardous to anyone visiting the island.
The Augustine summit area continues to emit noxious volcanic gases. A gas-rich plume is often present and areas downwind of the summit may be engulfed by variable amounts of volcanic gas. Where the plume hugs the ground near the volcano, the gases can cause eye irritation and respiratory problems. Gases can accumulate in low-lying or confined areas of the summit and lava flows, and it is possible, but not likely, that the concentration of gases in these areas could reach levels dangerous to humans.
Though the volcano is currently quiet, renewed eruptive activity is possible. AVO expects that a renewal of explosive activity or lava extrusion would likely be preceded by increases in seismicity, heat, gas output, and deformation.
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
Steve McNutt, Acting Coordinating Scientist, UAF
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.