Mt. St. Helens Erupts–A Look Back at Spring 1980

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Mt. St. Helens was once one of the most beautiful, pristine, symmetrical mountains in the world.   For thousands of years, it had reflected its grandeur in the huge, deep, crystal pure Spirit Lake.

Spirit Lake and Mt. St. Helens, pre-eruption. Photo from U.S. Forest Service.
Spirit Lake and Mt. St. Helens, pre-eruption. Photo from U.S. Forest Service.

Then in March 1980, Mt. St. Helens started to have earthquakes–“harmonic tremors”–the signaled the movement of magma.  The mountain started to puff up ash.

Mt. St. Helens initial ash plumes began in March 1980. Mt. Rainier is in background. Photo by C. Dan Miller
Mt. St. Helens initial ash plumes began in March 1980. Mt. Rainier is in background. Photo by C. Dan Miller

After the initial surprise, western Washington residents mostly saw it as a curiosity.  It became a day trip for people to drive to watch it billow dark ash.

Photo by Peter Lipman
Photo by Peter Lipman

People joked about the volcano, and radio stations played Jimmy Buffet’s song, “Volcano,” the title track from his new album at the time.  What an eery coincidence!

buffett volcano 2jimmy buffett volcano

 

 

 

 

We didn’t understand what was coming, although brave geologist Dave Johnston, 30, tried to warn us.   We mostly thought that the lava would pour out of the volcano top and leisurely roll down the side.  We didn’t understand that our volcanoes had thick magma, and would simply explode when they erupted.  Dave tried to tell us otherwise.

Dave Johnston collecting samples at Mt. St. Helens crater lake on April 30, 1980--two and a half weeks before he died in the eruption. USGS.
Dave Johnston collecting samples at Mt. St. Helens crater lake on April 30, 1980–two and a half weeks before he died in the eruption. USGS.

At 8:32 Sunday morning, May 18, 1980, Mount St. Helens erupted in a way that few could have imagined.

Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche.   In a few moments this slab of rock and ice slammed into beautiful Spirit Lake, crossed a ridge 1,300 feet high, and roared 14 miles down the Toutle River.

Geologist Dave Johnston had moved toward an ominous looking new bulge shortly before the eruption –

The avalanche rapidly released pressurized gases within the volcano.   A tremendous lateral explosion ripped through the avalanche and developed into a turbulent, stone-filled wind that swept over ridges and toppled trees.   Nearly 150 square miles of forest was blown over or left dead and standing.

At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and across several states.

Here is KOMO-TV’s Dave Crockett, looking back on that day at the mountain when he kept his camera rolling–even when he felt sure he was going to die.  His bone chilling video was shown over and over on KOMO during the days following the eruption –

This is how far the ash traveled-

Ash fallout accumulation and distribution. USGS.
Ash fallout accumulation and distribution. USGS.

 

Wet, cement-like slurries of rock and mud scoured all sides of the volcano. Searing flows of pumice poured from the crater. The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments.

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