ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, January 13, 2012, 12:44 PM AKST (Friday, January 13, 2012, 21:44 UTC)
52°49'20" N 169°56'42" W,
Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
No new activity was detected at Cleveland volcano this week. Elevated surface temperatures at the volcano's summit were observed in satellite images January 12. The elevated temperatures likely result from active fumaroles (vents of hot steam and gas) as well as from recent, still-warm deposits of ash, blocks, and lava. No lightning, airwave (infrasound) signals, or volcanic ash in satellite images were detected during this interval, indicating that the elevated temperatures were not related to volcanic explosions. AVO has received no reports of activity at the volcano from pilots or other observers.
Satellite data indicate that the lava dome that formed throughout the fall-winter of 2011 was largely removed and covered by the explosive activity of late December. It is uncertain if eruptive activity at Cleveland has ended, paused, or is occurring at a level below our detection capabilities. It remains possible for intermittent, sudden explosions of blocks and ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop. Such explosions and their associated ash clouds may go undetected in satellite imagery for hours. If a large, explosive, ash-producing event occurs, seismic, infrasound, or volcanic lightning may be detected by local and regional monitoring networks. There is no real-time seismic monitoring network on Mount Cleveland.
Additional information on Cleveland Volcano and the current activity may be found at this link:
Please see http://www.avo.alaska.edu/color_codes.php for complete definitions of Aviation color codes and Volcano alert levels.
Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located 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 it produced 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. The 2001 eruption also produced a rubbly lava flow and hot avalanche that reached the sea.
John Power, Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
Steve McNutt, Coordinating Scientist, UAF
email@example.com (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.