Printer friendly versionALASKA VOLCANO OBSERVATORY
Tuesday, August 14, 2007 4:30 PM AKDT (030 UTC)
55°24'57" N161°53'24" W, Summit Elevation 8261 ft (2518 m)
Current Aviation Color Code: YELLOW
Current Volcano Alert Level: Advisory
An abrupt increase in earthquake activity began at Pavlof Volcano on the Alaska Peninsula early this morning. Based on the patterns of unrest leading to past eruptions at Pavlof, AVO considers this a clear departure from background activity and we are elevating the alert level and color code to ADVISORY / YELLOW. The current activity may not lead to an eruption, however, similar patterns of seismicity occurred prior to eruptions in 1996, 1986, 1981, and 1983.
NWS observers in Cold Bay were able to see the volcano this morning and reported no anomalous steaming or other activity. Clear satellite imagery from this morning also showed no obvious signs of surface activity or ash emission. The area is currently cloudy.
The last eruption of Pavlof began in September, 1996 and was first reported by observers in Cold Bay. A several-month-long series of ash explosions, lava-fountaining, and lava-flow production ensued. Ash clouds reached as high as 30,000 ft ASL on one occasion, however, most ash clouds were below 20,000 ft ASL. Prior to 1996, Pavlof erupted in 1986 sending ash as high as 49,000 ft ASL on at least one occasion.
AVO will be increasing its monitoring frequency for Pavlof while at this heightened level of unrest.
Pavlof volcano is located on the southwestern end of the Alaska Peninsula about 590 miles southwest of Anchorage. The community of Cold Bay is located 37 miles to the southwest of Pavlof. Pavlof is a steep-sided, symmetrical, 8262-ft-high stratovolcano. With almost 40 historic eruptions, it is one of the most active volcanoes in the Aleutian arc. Eruptive activity is generally characterized by sporadic lava fountaining continuing for a several-month period. Additional hazards in the vicinity of the volcano included light ash fall on nearby communities, mudflows, lava flows and avalanching of hot debris on the flanks of the volcano. For more information on Pavlof and potential volcano hazards, please see our web site: http://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Pavlof
VOLCANO ALERT LEVELS:
NORMAL Typical background activity of a volcano in a non-eruptive state
ADVISORY Elevated unrest above known background activity
WATCH Volcano is exhibiting heightened or escalating unrest with increased potential for eruptive activity
WARNING Highly hazardous eruption underway or imminent
ABBREVIATED AVIATION COLOR CODE KEY:
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
Please see http://volcanoes.usgs.gov/2006/vhpalertlevel.pdf for a complete description of alert levels and color codes.
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, 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.