Alaska volcano remains active after morning blast

By George Bryon

McClatchy Newspapers

(MCT)

ANCHORAGE, Alaska _ Since an erupting Mount Redoubt sent an ash cloud shooting nearly 12 miles high early Monday morning with its fifth and strongest explosion, the Cook Inlet volcano has remained highly active, the Alaska Volcano Observatory reports.

Six to seven smaller, subsequent explosions lasting about two minutes apiece have sent additional ash and gas into the atmosphere since the big blast at 4:30 a.m., AVO staff scientist Chris Waythomas said.

Ash has now been detected at 60,000 feet above sea level, the National Weather Service reported.

Midlevel winds are still carrying the ash plume north over the Susitna Valley, and minor ash fall has been reported in Skwentna, Willow, Trapper Creek and Talkeetna, according to the Weather Service, the Matanuska-Susitna Borough and eyewitness reports. Traces of ash also have now been reported in Denali National Park and at the village of Nikolai to the west.

High-elevation winds above 40,000 feet are beginning to veer toward Anchorage, but no ash is expected to fall on Alaska's largest city at this time, Bob Hopkins, the meteorologist-in-charge of the National Weather Service office in Anchorage, said.

"Eight miles up _ that's going to stay there," Hopkins said. "But that will affect aircraft at that altitude."

It's the lower-elevation winds between 10,000 and 20,000 feet, currently blowing north by northeast, that are most likely to carry ash to the ground, Hopkins said.

In the Su Valley, the ash fall is being described as fine gray dust around Skwentna, Trapper Creek and Talkeetna.

The eruption has apparently destroyed the "RSO" seismometer on the south flank of the volcano, as well as the AVO webcam inside a hut six miles from the summit, Waythomas said.

Two additional seismometers on Redoubt's north and east slopes were nonoperational for a while Monday morning, but that was due to a power outage on the Kenai Peninsula, he said.

By midmorning, residents in Kenai began reporting a sulfur smell in the air, but no ash had yet fallen there and schools are open, officials said.

Redoubt began erupting Sunday night, with the first explosion coming at 10:38 p.m., followed by another at 11:02 p.m., a third at 12:14 a.m. and a fourth at 1:39 a.m., the AVO reported.

Ted Stevens Anchorage International Airport remains open, although some airlines have canceled or diverted flights. Alaska Airlines reported canceling 19 flights in and out of Anchorage because of the ash but other flights are operating.

Elmendorf Air Force Base reported that 60 planes, including fighter jets, cargo aircraft and a Boeing 747 commercial plane, are being sheltered. The base initially ordered only essential personnel to report for duty; that was later changed to all personnel reporting at 8 a.m.

Mount Redoubt, a 10,197-foot stratovolcano 100 miles southwest of Anchorage, last erupted during a fourth-month period in 1989-90. Its recent period of volcanic unrest began Jan. 25.

An official with the Federal Aviation Administration at the Anchorage airport early Monday said there were no immediate plans to close the airport.

The Weather Service advised people in areas of ash fall to seal windows and doors, protect electronics and cover air intakes and open water supplies as well as minimize driving.

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© 2009, Anchorage Daily News (Anchorage, Alaska).

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