Printer friendly versionALASKA VOLCANO OBSERVATORY
Friday, May 27, 2005 11:30 AM AKDT (19:30 UTC)
MOUNT SPURR VOLCANO (CAVW#1103-04)
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. In the past week, a slight increase in the number of long period earthquakes at depths of 20-35 km (12-22 mi) occurred beneath the volcano. No unusual activity was observed in clear to partly cloudy satellite and web camera images this past week. A small steam plume is occasionally visible above the summit crater at Spurr. 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.
MT. HAGUE VENT OF EMMONS LAKE CALDERA (CAVW#1102-02)
(HAGUE) 55°23' N 161°58' W, Summit Elevation 4,956 ft (1,512 m)
On May 23 and 24, National Weather Service personnel in Cold Bay reported steam plumes rising from Pavlof Volcano and the Mt. Hague vent of Emmons Lake Caldera on the lower Alaskan Peninsula. On Tuesday, a plume rose 3000 ft above the summit of Hague and may have contained small amounts of ash. Analysis of photographs and data from seismic stations from nearby Pavlof Volcano showed no seismicity that would indicate significant volcanic unrest. Mt. Hague has two nested summit craters with a lake in the south crater that contains vigorous fumaroles (small volcanic vents from which hot gases are emitted), as well as a fumarolic area on the southeast flank. Both areas have produced strong steam emissions in the past. Thus, AVO considers this activity to be a normal fluctuation of hydrothermal processes at Mt. Hague.
Mt. Hague is a small stratocone within Emmons Lake Caldera. It has had no reported historical eruptions, but has likely been active in the past 500 to 1000 years. Observations of steam from Pavlof Volcano are also normal and reflect typical background thermal activity high on the cone.
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
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
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
Steve McNutt, Acting-Coordinating Scientist, UAF-GI, email@example.com (907)
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.