A strong explosive eruption is underway at Okmok Volcano – See Okmok Volcano [Update #1]
AVO/USGS Volcanic Activity Notice
Volcano: Okmok (CAVW #1101-29-)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: RED
Steaming Cleveland volcano on July 27, 2007, its steep, slopes mantled by grey debris ejected from the summit crater during recent explosions. Even the snow patches on Tana, an older volcano on the eastern portion of Chuginadak Island about 12 km (7 mi) east, are slightly grey with a dusting of what is probably Cleveland ash. The prominent peak on the horizon is 7051-ft-tall Vsevidof volcano on southwestern Umnak Island. Picture Date: July 27, 2007 06:35:00 – Image Creator: Power, John. Credit: Andrew Rose and Maritime Helicopters
…
…
Issued: Saturday, July 12, 2008, 9:28 PM AKDT (20080712/0528Z)
Source: Alaska Volcano Observatory
Location: N 53 deg 23 min W 168 deg 9 min
Elevation: 3520 ft (1073 m) –
Area: Aleutians Alaska
Volcanic Activity Summary: A strong explosive eruption began at approximately 1943 Z (11:43 AM ADT) and continues at this time based on high levels of seismicity recorded on the AVO seismic network. Seismicity reached a peak at about 2200 Z (2:00 PM ADT) and has been gradually declining since. The main mass of the ash cloud is at least 35,000 feet above sea level and is moving generally southeast from the volcano, with lesser amounts of ash moving eastward. Ash fall has been reported on eastern Umnak Island and in Unalaska/Dutch Harbor.
…
…
…
…
…
….
….
AVHRR Thermal IR (Channel 4) satellite image at 00:15 UTC on July 13, 2008 of ash cloud from Okmok eruption cloud. – Picture Date: July 13, 2008 – Image Creator: Webley, Peter – Image courtesy of the AVO/UAF-GI
…
Recent Observations:
[Volcanic cloud height] The ash cloud is reaching in excess of 35,000 ft above sea level. Light winds appear to be carrying the ash cloud to the southeast and east at this time.
[Ash fall] Ash fall was reported soon after the eruption onset at Fort Glenn 7 miles southeast of the volcano. Ash fall began at Unalaska/Dutch Harbor at 3:45 pm ADT and is reportedly tapering off. Preliminary reports indicate only a light dusting has fallen so far.
[Other observations] U.S. Coast Guard aircraft in the area reported ash to at least 35,000 feet at 0130 Z on 13 July (5:30 PM ADT 12 July).
Location of Okmok volcano and other Aleutian volcanoes with respect to nearby cities and towns.
Picture Date: May 16, 2006 – Image Creator: Schaefer, Janet – Image courtesy of the AVO/ADGGS.
Hazard Analysis:
[General hazards] Ash fall is expected to continue downwind of the volcano including over marine areas in the North Pacific. Areas in the immediate vicinity of the volcano on Umnak Island should be avoided, particularly the Crater Creek drainage northeast of the caldera.
[Ash cloud] An ash cloud is drifting southeast and east of the volcano and poses a risk to aircraft in the vicinity. The estimated cloud height for the ash cloud is in excess of 35,000 ft above sea level.
[Ballistics] Ballistics may impact the areas around the caldera rim.
[Lava flow/dome] Historical eruptions of Okmok have typically produced lava flows, however at this time we cannot confirm that a lava flow has been produced.
Mission: ISS002 Roll: 715 Frame: 2 Mission ID on the Film or image: ISS002 Country or Geographic Name: USA-ALASKA Features: UMNAK ISLAND, VOLCANO Center Point Latitude: 53.5 Center Point Longitude: -168.5 * Picture Date: 2001 * Image Creator: Image Analysis Laboratory, NASA Johnson Space Center. Image courtesy of the Image Analysis Laboratory, NASA Johnson Space Center. Image Analysis Laboratory, NASA Johnson Space Center. Earth Sciences and Image Analysis, NASA-Johnson Space Center. 25 Mar. 2005. “Astronaut Photography of Earth – Display Record.”
Remarks: Okmok Volcano is located on the northeast end of Umnak Island in the eastern Aleutians about 65 miles southwest of Unalaska/Dutch Harbor. The volcano consists of a 6-mile-wide circular caldera or crater about 1600 feet deep that formed about 2000 years ago. Okmok has been frequently active in historical times producing ash clouds often accompanied by lava flows within the caldera. The most recent eruption occurred in 1997 and produced ash clouds and a lava flow that traveled about 5 miles across the caldera floor.
More information: http://www.avo.alaska.edu/activity/Okmok.php
Related Links: