Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, October 12, 2007 1:05 PM AKDT (2105 UTC)
52°49'20" N169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Aviation Color Code: YELLOW
Current Volcano Alert Level: Advisory
Retrospective analysis of seismic data indicates that an explosion occurred at Cleveland at approximately 03:49 ADT (11:49 UTC) October 3, 2007. A thermal anomaly was detected in satellite data on October 7, 2007. Since then, nothing unusual has appeared in mostly cloudy satellite views.
Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located about about 75 km (45 mi.) west of the community of Nikolski, and 1500 km (940 mi.) southwest of Anchorage. The volcano's most recent significant eruption began in February, 2001 and had 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. This eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in October 2006.
59°21'45" N153°26'6" W, Summit Elevation 4134 ft (1260 m)
Current Aviation Color Code: GREEN
Current Volcano Alert Level: Normal
Shallow, low-level seismic activity continued throughout the week at the volcano's summit, though at diminished intensity. Webcam and satellite views showed nothing unusual.
Because of declining seismic activity, and the lack of any other indicators of volcanic unrest, AVO lowered the aviation color code and volcano alert level to GREEN and NORMAL this morning.
Augustine Volcano is a 1260 m high (4134 ft) conical-shaped island stratovolcano located in southern Cook Inlet, about 290 km (180 mi) southwest of Anchorage, Alaska and 120 km (75 mi) southwest of Homer, Alaska. Historically, Augustine is the most active volcano in the Cook Inlet region with significant eruptions in 1812, 1883, 1908, 1935, 1963-64, 1976, 1986, and 2006. These eruptions were primarily explosive events that produced volcanic ash clouds (to 30,000-40,000 feet above sea level), ash fall, pyroclasic flows, and and lava domes or flows. During the 1883 eruption, a large avalanche on the north flank of the volcano flowed into Cook Inlet and may have initiated a tsunami observed at Nanwalek, about 90 km to the east.
OTHER ALASKA VOLCANOES
Seismic activity is monitored in real time at 31 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, Fourpeaked, Snowy, Griggs, Katmai, Novarupta, Trident, Mageik, Martin, Peulik, Ukinrek Maars, Aniakchak, Veniaminof, Pavlof, Dutton, Isanotski, Shishaldin, Fisher, Westdahl, Akutan, Makushin, Okmok, Korovin, Great Sitkin, Kanaga, Tanaga, and Gareloi volcanoes are at Aviation 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 volcano.
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
Tom Murray, Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
Jessica Larsen, Acting Coordinating Scientist, UAF
email@example.com (907) 474-7992
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.