The U.S. Geologic Survey warns that Mount Rainier near Seattle is getting ready to spew out another ton of mud, and that could be only the beginning of an eruptive period. USGS volcano monitor William E. Scott says it’s “a monumental threat.”
Blaine Harden writes in The Washington Post that volcanologists used to think Rainier was fairly stable, but now they’ve changed their minds. They want local emergency management officials to launch an early-warning system and a public awareness campaign telling people to “enjoy the volcano in your back yard” but to be prepared to run if necessary. Roads leading to and from Rainier have signs that read: “Volcano Evacuation Route.” They’re a tourist attraction, and keep getting stolen.
People who live in the town nearest Rainier have about 40 minutes to flee. Inside the national park that’s home to the mountain, people have about five minutes. No other volcano in the lower 48 states threatens so many people.
Mount Rainier is still an active volcano, and what’s worse, it’s rotting from the inside out, especially on its western side, which faces heavily populated areas. It has a history of spontaneously collapsing, causing massive mudflows called lahars.
About 150,000 people now live on top of lahars that were created over the past 5,000 years. The lahars stretch for 50 to 75 miles, all the way down to the ports of Tacoma and Seattle. If a lahar starts flowing, it will set off air-raid sirens that can be heard by about 30,000 people. Mount St. Helens, which erupted in 1980, killing 57 people, is more active than Rainier, but it’s not near large population areas.
“Lahar” means “volcanic mudflow” in Indonesian. The rot inside Rainier is caused by trapped gas, which turns the rock into clay the consistency of concrete, that can flow 40 miles an hour. Rainier “burps” a batch of this mud about every 500 to 1,000 years. “The bad news is that the window of opportunity is now open,” says Steve Bailey, director of emergency management for Pierce County, where damage is most likely. “The good news is that the window is 500 years long.”
Is this Seattle’s final hour?
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