AVO/USGS Volcanic Activity Notice Volcano: Okmok (CAVW #1101-29-) Current Volcano Alert Level: WARNING Current Aviation Color Code: RED Issued: Wednesday, July 16, 2008, 9:53 AM AKDT (20080716/1753Z) Source: Alaska Volcano Observatory Notice Number: 2008/A11 Location: N 53 deg 23 min W 168 deg 9 min Elevation: 3520 ft (1073 m) Area: Aleutians Alaska Volcanic Activity Summary: Okmok Volcano continues to erupt. Over the last 24 hours, activity at Okmok has diminished. Seismicity has changed from nearly continuous volcanic tremor to a more episodic character, and over the last several hours, the overall seismic intensity has declined. The most recent satellite imagery indicates little or no ash, however weather clouds may be obscuring an ash signal. At 05:33 this morning AKDT (13:33 UTC), thermal satellite imagery revealed elevated surface temperatures in the northeast sector of the caldera. Because of continuing unrest and uncertainty about the immediate future of the eruption, Okmok remains at aviation color code RED and alert level WARNING. All areas immediately around the volcano are considered hazardous. Airborne ash and gas continue to pose a hazard to aviation in the area. Additional ash fall will likely occur on Umnak Island and possibly adjacent islands as long as the eruption continues. Recent Observations: [Monitoring report] Seismicity has changed from nearly continuous volcanic tremor to a more episodic character, and over the last several hours, the overall seismic intensity has declined. Hazard Analysis: [General hazards] All areas immediately around the volcano are considered hazardous. Reports from Unalaska/Dutch Harbor indicate a light dusting of ash early this morning. [Ash cloud] As of about midnight this morning (08:00 UTC), satellite data continued to show a plume from the volcano reaching 30,000 feet above sea level. Remarks: Please see http://www.avo.alaska.edu/activity/Okmok.php for more information. Contacts: John Power, Acting Scientist-in-Charge, USGS jpower@xxxxxxxx, (907)786-7497 Steve McNutt, Coordinating Scientist, UAFGI steve@xxxxxxxxxxxxxxxxx (907)978-5458 Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu 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. ==============================================================
