Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, September 2, 2005 12:45 AM AKDT (20:45 UTC)
SPURR VOLCANO CAVW#(1103-04-)
61.3 ° W 152.25 ° N, Summit Elevation 11070 ft (3374 m)
Current Level of Concern Color Code: YELLOW
The level of seismic activity at Mt. Spurr volcano remains above background, similar to the levels of the past several weeks. The volcano was visible intermittently throughout the week in both web camera and satellite views, but no unusual activity was observed. Minor steaming may occur from the summit melt pit and occasionally from Crater Peak. Conditions at the volcano have not changed significantly in the past several weeks and there are no indications that an eruption is imminent.
Mount Spurr volcano is an ice- and snow-covered stratovolcano located on the west side of Cook Inlet. The only known historical eruptions occurred in 1953 and 1992 from the Crater Peak flank vent located 3.5 km (2 mi) south of the summit of Mount Spurr. These eruptions were brief, explosive, and produced columns of ash that rose up to 20 km (65,000 ft) above sea level and deposited several mm of ash in south-central Alaska, including approximately 6 mm of ash on Anchorage in 1953. The last known eruption from the summit of Mount Spurr was more than 5,000 years ago. Primary hazards during future eruptions include far-traveled ash clouds, ash fall, pyroclastic flows, and lahars or mudflows that could inundate drainages all sides of the volcano, but primarily on the south and east flanks.
CLEVELAND VOLCANO (CAVW #1101-24)
52°49’N 169°57’W, Summit Elevation 5,674 ft (1,730 m)
Current Level of Concern Color Code:Not assigned
A thermal feature has been detected in several satellite images obtained on August 31 this week but no evidence of eruptive activity has been observed. Also, AVO has received no pilot reports of activity. Cleveland volcano does not have a real-time seismic network and without seismic data, AVO has no definitive information about the level of activity of the volcano unless clear satellite views can be obtained. The presence of a thermal feature at the summit of the volcano may indicate that low-level activity could occur in the near future.
Historical eruptions at Cleveland volcano have been characterized by short-lived explosive bursts of ash, at times accompanied by lava fountaining, lava flows, and debris flows down the flanks. In February, 2001, Cleveland had 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. That eruption also produced a rubbly lava flow and hot avalanche that reached the sea.
ABBREVIATED COLOR CODE KEY (contact AVO for complete description):
GREEN volcano is dormant; normal seismicity and fumarolic activity occurring
YELLOW volcano is restless; eruption may occur
ORANGE volcano is in eruption or eruption may occur at any time
RED significant eruption is occurring or explosive eruption expected at any time
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
email@example.com (907) 786-7497
Steve McNutt, Acting-Coordinating Scientist, UAF-GI
firstname.lastname@example.org (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.