Mt. St. Helens: A Fact Sheet

The eruption of Mt. St. Helens in 1980 caught the United States volcano experts a little off guard.  It had been 65 years since the last mainland eruption.  It all began on March 20 when noises from the volcano became audible--and worrisome.  Within a week it was spewing magma every day all day accompanied by earthquakes.  People in the area were evacuated eight miles to safety.

It was at this point that Mt. St. Helens became the celebrity volcano, with cameras from all over the world focused on the light show.  TV crews crept too close to provide "film at eleven."  Helicopters by the dozen flew over the top of the mountain, daring the rumbling volcano to show its face.  But like a willful child who won't behave as instructed, Mt. St. Helens took its time deciding what it wanted to do.  News crews stopped their 24/7 coverage--an expensive proposition if the damn thing wasn't going to blow after all.

But then almost a month later on April 19, the northern side of the mountain began bulging threateningly with what should have been read as a forthcoming  lateral blast, but was not.  The experts missed the signs perhaps because the only volcanoes they had observed were in Hawaii, and they did not have lateral bulges and explosions.

Another month passed.  Then on Sunday May 18 at 8:32 in the morning it began.  Bill Bryson described what followed in his Short History of Nearly Everything (2003):  "The north side of the volcano collapsed, sending an enormous avalanche of dirt and rock rushing down the mountain slope at 150 miles an hour.  It was the biggest landslide in human history and carried enough material to bury the whole of Manhattan to a depth of four hundred feet.  A minute later, its flank severely weakened, St. Helens exploded with the force of five hundred Hiroshima-sized bombs, shooting out a murderous hot cloud at up to 650 miles an hour--much too fast, clearly, for anyone nearby to outrace.  Many people who were thought to be in safe areas, often far out of sight of the volcano, were overtaken.  Fifty-seven people were killed.  Twenty-three of the bodies were never found.  The toll would have been much higher except that it was a Sunday.  Had it been a weekday many lumber workers would have been working within the death zone.  As it was, people were killed eighteen miles away."

The facts:  Mt. St. Helens lost 1,300 feet from its peak. 230 square miles of forest were destroyed.  Damage was reported at $2.7 billion. The smoke and ash rose 60,000 feet in ten minutes.  The town of Yakima, Washington, 80 miles away, got covered in ash and smoke an hour and a half after the blast.

                                      At Mt. St. Helens in the Cascade Mountains, 31 years
                                      after the eruption in 1980 that blew 1,300 feet off the
                                      volcano's summit.  Photo by Roberta Cifelli, 2011.