5,600 years ago, the summit of Mt Rainier stood 1,000 feet (304 m) higher than today. Then came a giant eruption and the side of the volcano failed, sending a wall of mud careening down the White River Valley all the way to Tacoma and Puget Sound, 40 miles away.
Originally published on Jan 19, 2017
Known as the Osceola MudFlow, up to 500 feet of “liquid cement,” as Nick puts it, shot down the valley at speeds up to 50 miles an hour to creat the Enumclaw Plain by burying the Puget Lowland with hundreds of feet of volcanic mud.
Today, the plain is home to more than 500,000 people.
Nick Zentner is the science outreach and education coordinator for the Department of Geological Sciences at Central Washington University. He has produced more than 40 short videos about Central Washington geology.