Saturday, February 28, 2009
Alaska: Some schools are preparing for eruption
Some Alaskan schools are making preparations in advance of what scientists say is an "imminent" eruption from the 10,200-foot Redoubt Volcano, about 100 miles southwest of Anchorage.
Scientists from the Alaska Volcano Observatory (AVO) set the observatory's alert level on a "watch" for a possible eruption after the mountain experienced tremors and elevated seismic activity, including a sharp increase in earthquakes underneath the mountain.
Geologists flew to Mount Redoubt to collect gas samples and look for signs of an eruption after a steam plume was again spotted Feb. 7, near a dome that formed after the last eruption in 1990.
Alaska's volcanoes are not like Hawaii's. "Most of them don't put out the red river of lava," said AVO's John Power. Instead, they typically explode and shoot ash 30,000 to 50,000 feet high--more than nine miles--into the jet stream.
The Anchorage School District's (ASD) web site features information about a possible eruption and encourages schools to prepare in advance. The web site says scientists predict that it would take at least two and a half hours for ash from an eruption to travel to the Anchorage area.
"Our response will depend on the timing and severity of the ashfall," said a district spokesperson.
ASD's Departments of Instruction, Maintenance, Transportation, Risk Management, Emergency Preparedness, and others have reviewed emergency plans and have plans for dealing with a variety of scenarios. The district will contact employees and parents with critical information and shelter-in-place, if necessary, in the event of a disruption during the school day.
District officials said that emergency information will be available on a specific television channel, on ASD's web site, through a telephone recording, and through major media.
Purchasing N95 dust masks, using eye goggles or other protection, and buying extra air and oil filters for vehicles will help citizens prepare for a possible ashfall. A wet handkerchief or piece of fabric can take the place of a dust mask. People, especially young children, the elderly, and those with respiratory conditions, are advised to stay indoors. Pets should be brought indoors as well.
The ash from an eruption can injure skin, eyes, and breathing passages.
"It's a very abrasive kind of rock fragment," Power said. "It's not the kind of ash that you find at the base of your wood stove." The particulate has jagged edges and has been used as an industrial abrasive and to polish metals.
It's also potentially deadly for anyone flying in a jet.
"Think of flying an airliner into a sandblaster," Power said.
The jet stream can carry ash for hundreds of miles. Ash from Kasatochi Volcano in the Aleutians last August blew all the way to Montana and threatened aircraft, Power said.