Sunday, May 16, 2010

The Day The Earth Roared



This Tuesday is the 30th anniversary of the eruption of Mount St. Helens. I remember that day vividly, even though I was 9 years old and lived 2,500 miles away. I was already fascinated with mountains, so the images that appeared on the news -- of a beautiful peak blowing itself up and raining catastrophe on everything in sight -- made an indelible impression.

A series of steam eruptions had already occurred in the two months before the big one. They had opened a new crater and generated two fractures on St. Helens’s north flank. Between those fractures, the mountainside expanded outward in a visible bulge. In other words, it was obvious that St. Helens was waking up and that a bigger eruption was possible; but still, nobody expected anything like what eventually happened. After all, the frequency of steam eruptions had decreased from March to April.

Then, at 8:32 on the morning of May 18, 1980, St. Helens exploded with the force of five atomic bombs. Its summit was blown off, lowering its elevation from 9,677 to 8,363 feet. And its north flank was ripped out, leaving an immense gap and ruining the perfect symmetry for which the mountain had been famous.

The eruption’s ash cloud reached 80,000 feet high within 15 minutes, and as the ash fell back to earth, an area of 22,000 square miles was covered by measurable amounts. Borne by wind, St. Helens ash particles spread across the United States in three days and circled the globe in two weeks.

A landslide buried the North Fork of the Toutle River beneath debris that averaged 150 feet deep.

Lahars destroyed 185 miles of roads and 15 miles of railways, and reduced the depth of the Columbia River’s channel from 40 feet to 14 feet.

Trees snapped like matchsticks, as you can tell from this picture. And the area around St. Helens was instantly transformed from a forested wilderness to a barren moonscape, as evidenced by these before and after photos:






Sadly, that day's greatest tragedy is often overlooked: 57 people were killed.

Most people thought it would be many decades before life could return to St. Helens’s blast zone. However, greenery began to reappear on the slopes within a couple years, and that was after spiders and beetles ventured in. Eventually elk returned to feed on the new growth, and today the St. Helens recovery is an ongoing marvel.

Modern people often think that nature is fragile, but Mount St. Helens shows the opposite to be true. In reality, nature is powerful and resilient beyond our ability to comprehend.

To see some news footage from the time of the blast, go here.

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