Alert level raised for Alaska volcano

posted by: Dan Boniface 3 hrs ago

ANCHORAGE, Alaska (AP) – Increased earthquake activity has prompted scientists to raise the alert level for Alaska's Mount Redoubt volcano.

Geologists at the Alaska Volcano Observatory said Sunday that seismic activity had increased over the past two days. On Sunday morning, 40 to 50 earthquakes were being recorded every hour.

Scientists said conditions may evolve rapidly and culminated in an eruption within days to weeks at the volcano roughly 100 miles southwest of Anchorage.

A steam plume rising about 1,000 feet above the mountain peak was observed Saturday.

The observatory had warned in late January that an eruption could occur at any time.

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http://www.9news.com/news/world/article.aspx?storyid=112333

Redoubt

Mount Redoubt rises to 3108 m on the west side of Cook Inlet, 170 km SW of Anchorage. Redoubt volcano was constructed over a basement of glacially eroded Mesozoic granitic rocks, seen here in the foreground. The volcano has been very active during the Holocene, producing at least 30 tephra layers in the Cook Inlet basin stratigraphy. A steam plume rises from the summit crater, which is breached to the north, in this view from the NW following its 1989-90 eruption. Iliamna volcano is visible in the left distance.

Photo by Christina Neal (U.S. Geological Survey, Alaska Volcano Observatory).

http://www.volcano.si.edu/world/volcano.cfm?vnum=1103-03-&volpage=photos&photo=052033

Country: United States
Subregion Name: Southwestern Alaska
Volcano Number: 1103-03-
Volcano Type: Stratovolcano
Volcano Status: Historical
Last Known Eruption: 1990
Summit Elevation: 3108 m 10,197 feet
Latitude: 60.485°N 60°29'7"N
Longitude: 152.742°W 152°44'31"W

Redoubt is a 3108-m-high glacier-covered stratovolcano with a breached summit crater in Lake Clark National Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has been the most active Holocene volcano in the upper Cook Inlet. The volcano was constructed beginning about 890,000 years ago over Mesozoic granitic rocks of the Alaska-Aleutian Range batholith. Collapse of the summit of Redoubt 10,500-13,000 years ago produced a major debris avalanche that reached Cook Inlet. Holocene activity has included the emplacement of a large debris avalanche and clay-rich lahars that dammed Lake Crescent on the south side and reached Cook Inlet about 3500 years ago. Eruptions during the past few centuries have affected only the Drift River drainage on the north. Historical eruptions have originated from a vent at the north end of the 1.8-km-wide breached summit crater. The 1989-90 eruption of Redoubt had severe economic impact on the Cook Inlet region and affected air traffic far beyond the volcano.

http://www.volcano.si.edu/world/volcano.cfm?vnum=1103-03-

There is more about other volcanos of the world on that site also