ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, April 13, 2012, 10:55 AM AKDT (Friday, April 13, 2012, 18:55 UTC)
60°1'55" N 153°5'30" W,
Summit Elevation 10016 ft (3053 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Seismic activity at Iliamna Volcano remains slightly above background. Nothing unusual observed in web camera and satellite images over the past week.
The current activity at Iliamna does not indicate an imminent or certain eruption. A similar seismic swarm at Iliamna in 1996-1997 was not followed by eruptive activity. Prior to an eruption, AVO would expect to see a further increase in earthquake activity.
52°49'20" N 169°56'42" W,
Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
The low-level eruption of Cleveland Volcano continues. Slightly elevated surface temperatures were observed in satellite data during periods of clear weather, but there has not been renewed extrusion of lava. Several small ash-poor explosions have been detected by distant infrasound (air pressure) and seismic networks over the past week. The most recent of these explosions was this morning at approximately 8:04 am AKDT (1604 UTC). A weather cloud deck with a top of about 15,000 ft above sea level obscured the volcano, but there was no evidence of an eruption cloud rising above it.
While the volcano remains active, sudden explosions of blocks and ash are likely. It is possible for associated ash clouds to exceed 20,000 feet above sea level. If a larger ash-producing event occurs, seismic, infrasound, or volcanic lightning networks should detect the event and alert AVO staff. There is no real-time seismic monitoring network on Mount Cleveland so AVO is unable to track activity in real time.
Seismic activity is monitored in real time at 29 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. Akutan, Aniakchak, Augustine, Dutton, Fisher, Fourpeaked, Gareloi, Great Sitkin, Griggs, Isanotski, Kanaga, Katmai, Mageik, Makushin, Martin, Novarupta, Okmok, Pavlof, Redoubt, Shishaldin, Snowy, Spurr, Tanaga, Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof, and Westdahl volcanoes are in color code GREEN
and volcano alert level Normal. 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 of these volcanoes.
Please see http://www.avo.alaska.edu/color_codes.php
for complete definitions of Aviation color codes and Volcano alert levels.
VOLCANO INFORMATION ON THE INTERNET: http://www.avo.alaska.edu
RECORDING ON THE STATUS OF ALASKA'S VOLCANOES (907) 786-7478
John Power, 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.