Wednesday, November 24, 2010

Excitement in the Northwest

It was mid-morning on May 18, 1980, when a very puzzled and hesitant Helena radio DJ announced: "Er, you might want to put your car in the garage. They say Mount St. Helens has exploded, and ash is coming our way." I was every bit as puzzled as the DJ - St. Helens was good 500 miles to the west - but I dutifully drove my car into my seldom-used garage. Within hours, a light gray powder began to accumulate atop the freshly budded leaves of every shrub in my yard.

It is possible this is not the most exciting volcano-eruption story you've ever heard, but it was mine. I even brushed ash from my lilac leaves into vials - tangible proof for posterity!

The closer you were to the volcano, of course, the more exciting things got. In Spokane, some 200 miles from the blast, ash turned day into night. Ash in the air circled the globe in 15 days.

On or near the mountain, things were rather more serious. A final, 5.1 magnitude earthquake under the mountain - the last of 10,000 smaller quakes during the preceding few months - set off the blast, which caused the north side of the peak to give way. It was the largest landslide in the Earth's recorded history. Mudflows created by steam and ash combined with snow and water rushed down the Toutle River, taking out 27 bridges. Energy released by the eruption was equal to 27,000 Hiroshima nuclear bombs.

You want an exciting story? The last words radioed by volcanologist David Johnston from near the summit were: "Vancouver! Vancouver! This is it!"

Unfortunately, the story of volcanoes in the Pacific Northwest gets more exciting still. Mount Rainier, the tallest peak in the Cascades, looms above Seattle and Tacoma, still active, poised to erupt at any time. (Many Seattle homes were built on former mudflows.) When earthquake swarms inevitably begin rumbling beneath Rainier, millions of people had better do more than drive their car into the garage.

1 comment:

  1. Good blog about one of my favorite subjects, Mount St. Helens. Though from WA, we were in West Africa in the tiny country of The Gambia, serving with the Peace Corps,when MSH gave its all. One of the first things we did when we returned was visit the mountain and we have been regular visitors since. I captured many of the incidences in my third novel, Tenderfoot--the research was fascinating.