UW professor: Deadly Guatemala lahar could happen here

A University of Washington professor says the heartbreaking images of death and devastation coming from the Guatemalan volcano and lahar should serve as an urgent warning to be familiar with a local lahar warning plan.

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Students in Puyallup River Valley schools in the shadow of Mount Rainier, like Sumner, are taught to instantly react and run to higher ground during an actual lahar warning — and students say the devastation in Guatemala reinforces that drill.

“I heard there’s gonna be a huge landslide when it happens here, and so all that debris is gonna come down,” said Dakota Altomary, who has been through lahar warning drills in school for four years.

UW professor George Bergantz says when the lahar alarm goes off, you may have a mere 15 minutes to react. “You may have even even less time than that, depending on where you live,” he said.

Professor Bergantz says the devastation happening now from the volcano eruption in Guatemala is exactly the same as what could and someday will happen below Mount Rainier. Simulations show Mount Rainier’s potential lahars would seek river valleys, bury them in debris, and 250,000 people would have precious minutes to react.

“That direction is always to higher ground,” said Bergantz. “Do not get in your car and try to drive away, do not try to run into the house and gather your goods. Get either on the roof of your house, or to adjacent higher ground as rapidly as possible. That’s the safest response.”

From above, a lahar might look like a muddy tsunami, but Bergantz says it’s a slurry of super-hot concrete made of rock, mud and debris flowing at 50 miles per hour, and its destructive power is hard to imagine.

Bergantz says the Guatemalan people seen in social media video running from a lahar’s deadly hot flow are actually in mortal danger. He says when the flow is seen slamming into a bridge, it sends a huge plume of 700-degree super-heated ash and gas billowing into the air – and he said it’s deadly dangerous even to be near it.

“If you inhale any of that or any of that ash, it will immediately clog your lungs, burn your lungs, and many of the people who die from this kind of hazard are dying because of suffocation.”
Bergantz says the entire Puyallup River Valley is made of solidified lahar flow that was once part of Mount Rainier, when 5,000 years ago, it unleashed a 500-foot wall of hot mud and rock.

“One shouldn’t think of the lahar alarm as a signal to start driving away to safety. It means that the fuse is lit and the time to respond and move to high ground is now.”

Dakota Altomary said every time she sees the mountain, it’s a reminder. “That mountain is active, and that could go off anytime now,” she said.