People Need as Much Warning as Possible to Flee Lahars; Feds Hope New Equipment Helps

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New detection systems on Mount Rainier could give Puyallup Valley residents extra minutes to flee a lahar, federal officials say.

The U.S. Geological Survey and Department of the Interior added five new monitoring sites at Mount Rainier National Park this month in an effort to upgrade and expand 11 lahar monitoring stations.

The upgrades include a seismometer to detect ground vibrations and infrasound sensors to detect pressure waves in the air.

"Infrasound has been shown around the world to be an important way for detecting explosions at volcanoes as well as pressure waves created by moving surface events such as landslides, avalanches and lahars," Seth Moran, the scientist in charge at the USGS Cascades Volcano Observatory said.

Data will be transmitted in real-time to the U.S. Geological Survey's office at the Cascades Volcano Observatory in Vancouver, Washington, and emergency operation centers.

The older monitors installed in 1998 sent "OK or not" messages every two minutes to federal and county agencies on whether there has been detected lahar activity.

"Within minutes of an event, you can now get a text out and let people know. It's all that harnessing new communication and data that can save lives," Moran said. "Every minute, every second counts."

The detection systems include a pole with an infrasound cone and a 5-foot square box with batteries, electronics, a radio, with solar panels mounted on the outside that keep the batteries charged.

Lahars make Mount Rainier one of the most dangerous volcanoes in the world. A lahar is ice and snow from the mountain's peak melting during an eruption and forming a hot mudslide that can travel up to 40 mph. At that speed, a hot mudslide could reach Orting in as little as 40 minutes and the Tacoma Tideflats within two hours.

The last lahar from Mount Rainier was in the year 1500 and was not caused by a volcanic eruption. A weak section on the west side of the volcano collapsed under the weight of the rock and ice.

Moran said the project focused on adding more monitoring systems to the western face because that's historically where there have been lahars.

"It looked like a slope failure. We've been able to locate where that happened and it's highest probability that that's where it will fail again," Moran said.



Another 12 proposed monitoring sites are on schedule to be installed by next September.

The added lahar detection systems on Mount Rainier are part of a larger effort to monitor Cascades volcanoes. Washington's Mount Baker, Glacier Peak, Mount Rainier and Mount St. Helens are deemed very high threats, as are Oregon's Mount Hood, Three Sisters, Newberry and Crater Lake.

The goal is to ensure that all U.S. volcanoes have monitoring networks that are commensurate with the threat they pose to society, Moran said.

The $11.7 million federal project allocates $1 million to upgrade Mount Rainier's monitoring systems.

Deputy Secretary of the Interior Katharine MacGregor said the Trump administration has made early detection of volcanic eruptions a priority.

"We do an awful lot for not a lot of money," she said. "We want to get the operations up and running as fast as possible."

Pierce County recently bolstered its preparedness for lahars and other natural disasters. The county added 27 more sirens in populated areas of the Puyallup River Valley and Nisqually River Basin that will sound when a lahar is detected.

The public is encouraged to share thoughts on the new lahar detection systems throughout October through the National Parks Service website.

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