Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, July 1, 2005 12:45 PM AKDT (20:45 UTC)
MOUNT SPURR VOLCANO
61°18' N 152°15' W, Summit Elevation 11,070 ft (3,374 m)
Current Level of Concern Color Code: YELLOW
Elevated levels of seismicity continue to be recorded at Mount Spurr with little change from the previous several weeks. No unusual activity was observed in satellite and web camera images this past week. During times of calm air, a small steam plume may be occasionally visible above the summit crater. Conditions do not indicate that an eruption is imminent.
Gases emitted by Spurr and Crater Peak may be hazardous to recreational visitors. Skiers, snowboarders, mountaineers, and pilots (especially those landing near the summit area) will find information regarding proximal hazards online at: http://www.avo.alaska.edu/activity/Spurr.php
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.
52°49’N 169°57’W, Summit Elevation 5,674 ft (1,730 m)
Current Level of Concern Color Code: Not assigned
Increased heat flow was detected and a possible debris flow observed in satellite images this past week. Although observations were limited by cloudy weather, they indicate the possibility of increased activity. Cleveland volcano is not seismically monitored, so satellite images are the primary source of information. AVO is not assigning a level of concern color code at this time due to the lack of seismic monitoring and limited satellite observations, but may do so if additional observations are received.
Mt. Cleveland 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. Historical eruptions at Mt. Cleveland have been characterized by short-lived explosive bursts of ash, at times accompanied by lava fountaining, lava flows, and debris flows down the flanks. The volcano's most recent 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.
OTHER ALASKA VOLCANOES
Seismic activity is monitored in real time at 28 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. Wrangell, Redoubt, Iliamna, Augustine, Snowy,Griggs, Katmai, Novarupta, Trident, Mageik, Martin, Peulik, Aniakchak, Veniaminof, Pavlof, Dutton, Isanotski, Shishaldin, Fisher, Westdahl, Akutan, Makushin, Okmok, Great Sitkin, Kanaga, Tanaga, and Gareloi volcanoes are in color code GREEN. 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.
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, firstname.lastname@example.org (907) 786-7497
John Eichelberger, Coordinating Scientist, UAF-GI, email@example.com (907) 474-5530
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.