Printer friendly versionALASKA VOLCANO OBSERVATORY
Monday, December 12, 2005 3:005 PM AKST (0005 UTC)
59.3633°N 153.4333°W, Summit Elevation 4134 ft (1260 m)
Current Level of Concern Color Code: YELLOW
A steam plume extending at least 75 km (45 mi) SE from Augustine Volcano is clearly visible by satellite and has also been reported by local pilots. Images in the web camera also show a plume. The plume appears to be primarily steam.
During the past several days, AVO has detected changes in the style of earthquake activity and received other information about gas emissions and steaming at Augustine Volcano. Two seismic events on Friday evening (12/9/05), and Sunday evening (12/11/05) may have perturbed the hydrothermal system, initiating steam explosions. These events are consistent with reports of steaming at the summit observed on Saturday (12/10/05), and distinct sulfur smell ("like from a sewer") in the air on Sunday evening (12/11/05) at Nanwalek and Port Graham, approximately 80 km (50 mi) east of the volcano. Collectively, these events are signs of continued and elevated level of volcanic unrest, but do not indicate that an eruption is imminent in the next few days to weeks. The level-of-concern color code remains at Yellow and AVO will continue to monitor activity closely.
Depending on the direction of the wind and the amount of gas emitted at the volcano, sulfur odors may persist. Periods of foul smelling air may accompany the present level of unrest at Augustine, but these periods should be relatively brief and are not expected to be a significant health concern. Humans can detect at very low concentrations the volcanic gases sulfur dioxide and hydrogen sulfide. At higher concentrations (or if a person has respiratory problems) the gases can irritate the eyes and respiratory system. People with respiratory problems should take reasonable precautions as they would for dealing with other types of slightly unhealthy air. See http://www.ivhhn.org/ "guidelines and databases" for more information.
A report describing the hazards associated with eruptions and other types of volcanic activity at Augustine Volcano can be obtained at http://www.avo.alaska.edu/pdfs/augustine_ofr.pdf
Augustine Volcano is a 1260 m high (4134 ft) conical-shaped stratovolcano located on Augustine Island in southern Cook Inlet, about 290 km (180 mi) southwest of Anchorage, Alaska. Augustine is the most historically active volcano in the Cook Inlet region. Historical eruptions occurred in 1812, 1883, 1908, 1935, 1963-64, 1976, and 1986. These eruptions were primarily explosive events that produced volcanic ash clouds and pyroclastic flows. During the 1883 eruption, a volcanic rock avalanche occurred on the north flank of the volcano; it flowed into Cook Inlet and initiated a tsunami observed at Nanwalek, about 90 km to the east.
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
Chris Nye, Acting Coordinating Scientist, UAF-GI
email@example.com (907) 590-3111
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.