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ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, October 19, 2012 2:29 PM AKDT (Friday, October 19, 2012 22:29 UTC)


CLEVELAND VOLCANO (CAVW #1101-24-)
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Cloudy to partly cloudy conditions were observed in satellite and webcam images at the volcano during the past week. No unusual activity has been reported.

Sudden explosions of blocks and ash remain possible with little or no warning, although the last confirmed explosion occurred on August 20. Ash clouds, if produced, could exceed 20,000 feet above sea level. If a large ash-producing event occurs, nearby seismic, infrasound, or volcanic lightning networks should alert AVO staff quickly. However, for some events, a delay of several hours is possible. There is no real-time seismic monitoring network on Mount Cleveland and AVO is unable to track activity in real time.

ILIAMNA VOLCANO (CAVW #1103-02-)
60°1'55" N 153°5'30" W, Summit Elevation 10016 ft (3053 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Seismicity remains somewhat elevated. Web camera and satellite views of Iliamna from the past week show mostly clear conditions.

Last Friday evening, October 12, at 8:16 pm AKDT (4:16 Saturday UTC) a rock and snow avalanche occurred at Iliamna, originating from a large rock face adjacent to the northernmost fumaroles near the summit. The slide measured 200 m wide and ran at least 2.8 km down the eastern flank onto the Red Glacier. The dark-colored slide was visible the following day to residents on the Kenai Peninsula, 80 km to the east across Cook Inlet. The duration (6-10 minutes), and the run out (nearly 3 km) corresponds to a flow speed of 5-9 m/s. The upper east flank of Iliamna is known to produce large avalanches, most recently in 2005.


LITTLE SITKIN VOLCANO (CAVW #1101-05-)
51°57'11" N 178°32'8" E, Summit Elevation 3898 ft (1188 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Seismic activity remains elevated. Mostly cloudy conditions were observed in satellite images during the past week. AVO has received no reports of unusual activity at the volcano.

OTHER ALASKA VOLCANOES

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

CONTACT INFORMATION:
John Power, Scientist-in-Charge, USGS
jpower@usgs.gov (907) 786-7497

Jeff Freymueller, Coordinating Scientist, UAFGI
jeff.freymueller@gi.alaska.edu (907) 378-7556

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.