ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE Friday, March 27, 2009 3:43 PM AKDT (Friday, March 27, 2009 23:43 UTC) REDOUBT VOLCANO (CAVW #1103-03-) 60°29'7" N 152°44'38" W, Summit Elevation 10197 ft (3108 m) Current Aviation Color Code: RED Current Volcano Alert Level: WARNING The 2009 eruption of Redoubt Volcano, which began on March 22 at 22:38 AKDT (6:38 UTC March 23), continues. The eruption has been characterized by powerful ash explosions, with the resulting plumes reaching between 30,000 to 60,000 feet above sea level. In all, the Alaska Volcano Observatory (AVO) has observed 11 major explosive events over the last week. The larger explosions have been associated with lahars in the Drift River Valley and trace to minor ash fall in and around the volcano and in areas across south-central Alaska. There have been no explosions of Redoubt Volcano since this morning March 27 at approximately 08:40 AKDT (16:40 UTC) and seismicity has declined at the volcano. The National Weather Service continues to track the ash cloud from the latest explosion, which is tracking toward the north-northwest. For ash fall advisories, refer to the National Weather Service Redoubt Coordination web page http://pafc.arh.noaa.gov/volcano.php AVO is monitoring the situation closely and the observatory is staffed 24/7. Based on its past activity, the current Redoubt eruption is expected to continue for weeks to months. During this time, a cycle of relatively quiet periods of lava dome growth followed by explosive episodes of dome destruction could take place. Future explosions pose an ongoing threat of lahars in the Drift River Valley, trace to minor ash fall throughout south-central Alaska, and ash-related impacts to aviation. Heavily ice-mantled Redoubt volcano is located on the western side of Cook Inlet, 170 km (106 mi) southwest of Anchorage and 82 km (51 mi) west of Kenai, within Lake Clark National Park. Redoubt is a stratovolcano which rises to 10,197 feet above sea level. Recent eruptions occurred in 1902, 1966-68, and 1989-90. The 1989-90 eruption produced mudflows, or lahars, that traveled down the Drift River and partially flooded the Drift River Oil Terminal facility. The ash plumes produced by the 1989-90 eruption affected international air traffic and resulted in minor or trace amounts of ash in the city of Anchorage and other nearby communities. CLEVELAND VOLCANO (CAVW #1101-24-) 52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m) Current Aviation Color Code: YELLOW Current Volcano Alert Level: ADVISORY AVO has received no new reports of activity at Cleveland over the past week. Partly cloudy satellite views show nothing unusual. 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 January 2009. 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. Akutan, Aniakchak, Augustine, Dutton, Fisher, Fourpeaked, Gareloi, Great Sitkin, Griggs, Iliamna, Isanotski, Kanaga, Katmai, Korovin, Mageik, Makushin, Martin, Novarupta, Okmok, Pavlof, Shishaldin, Snowy, Spurr, Tanaga, Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof, Westdahl, and Wrangell 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 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 CONTACT INFORMATION: Tom Murray, Scientist-in-Charge, USGS tlmurray@xxxxxxxx (907) 786-7497 Steve McNutt, Coordinating Scientist, UAF steve@xxxxxxxxxxxxxxxxx (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. ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
