When Mt. St. Helens Blew Her Top

The quiet of the early morning hours on Sunday, May 18, was violently and suddenly shattered when a blast 2,500 times as great as the atomic bomb that fell on Hiroshima was heard and felt throughout southwestern Washington State and northwestern Oregon. Mt. St. Helens, about 45 miles northeast of the Portland-Vancouver area, had suddenly erupted

THE story of the Mt. St. Helens eruption began in March, when scientists began monitoring earthquakes on and under the mountain itself. Those quakes were a clear signal of what was to come to pass on March 27 and again in May. The first signs of volcanic activity were noticed on March 27. There were minor eruptions of steam, and the earthquakes were coming on a daily basis.

Mt. St. Helens was 9,677 feeta tall and provided a majestic view to those who enjoy snowcapped peaks with green forests and beautiful lakes. Since the May 18 blast, all that is gone. About May 10, geologists noticed that a bulge was growing on the north side of the mountain at a rate of four to six feet a day. Eight days later the mountain caught virtually everyone off guard with a blast that was felt some 200 miles away.b

Tons of smoke and ash were blown high into the air, to descend later and settle four to six inches thick in places. At the time, winds were blowing in an easterly direction, and the ash fell as far east as Montana, with fine ash 40,000 feet high moving over New York city and out to sea.

Breathing became extremely difficult, and the health hazard was especially great to those having respiratory problems. Animals were seen lying down, their lungs filled with the fine ash. Automobiles were stalling as the ash clogged air filters. It irritated eyes and nasal passages and generally made life miserable for days after the eruption. Cities in eastern Washington got out their snow equipment and plowed the streets. Home owners were forced to clean walkways and clear roofs to keep the buildup of ash from getting too heavy. All crops in the eastern part of the state were blanketed.

The Devastation

The Mt. St. Helens eruption covered some 160 square miles, laying waste everything in its path. Near the mountain the devastation was unbelievable. The blast flattened over 55 square miles of timber and other vegetation. The intense heat completely burned off all the green foliage, and from the air it looked like the terrain was covered with a carpet of matchsticks. Nearby Spirit Lake, once a sparkling jewel set in majestic mountains, was filled with logs and mud. Mountain streams, such as the Toutle and Cowlitz Rivers and others, even including the mighty Columbia, were choked with tons of debris washed down from the mountain.

So much debris eventually found its way downstream that some nine and a half miles of the Columbia River was filled to the point that no ships could navigate it. The Army Corps of Engineers in cooperation with the Port of Portland and the Port of Vancouver began working day and night to clear a shipping channel. A 35-foot channel was started with 10 huge dredges. The task of removing some 22 million cubic yards of debris was begun, at an estimated cost of $44 million.

Cost in Dollars

The total cost was not immediately known, but government officials say that the total bill will run into the thousands of millions of dollars. Loss from crops could run into millions. Lost revenue from the ports of Portland and Vancouver was nearly $5 million daily as long as the Columbia River was closed. Total loss in timber leveled was estimated at $500 million​—some equated it to the loss of 200,000 single-family dwellings. Agriculture in eastern Washington could lose some $313 million, but the experts say that that figure is minimal and may have to be revised upward. Damage to national forest lands, $134 million. The list goes on and on.

Perhaps the extent of damages will never be known, but one thing is certain​—it is extensive and staggers the imagination.

The Human Element

The most tragic part of the Mt. St. Helens story is the fact that over a score of persons died and scores of others are missing. It is believed that many of those missing were simply vaporized by the tremendous heat from the initial explosion. It is reported that one man, some 15 miles from the heart of the blast, received third-degree burns and another one died due to the heat. Others died from inhaling excessive amounts of ash.

One old-time resident of Spirit Lake felt that he was secure and that the timber on the hills would prevent anything from the mountain from coming in his direction. A few short minutes after the blast nothing was alive in that area.

Many took unnecessary risks by going to the mountain in spite of the warnings, others risked their lives to make money as a result of the devastation. For example, the Toutle and Cowlitz Rivers were filled with tons of logs and debris. People were seen in small boats, and even on the logs, endeavoring to retrieve them.

Because of the ash fallout, residents east of Mt. St. Helens were advised to wear masks or respirators to protect their lungs. Some merchants sold these at exorbitant prices, while others were selling car air filters for $30 and more.

While there were these kinds of persons, the majority were very cooperative and eager to help. Driving in the area was reduced to speeds of 15 miles per hour. Most complied, and in many ways were helpful.

What About the Future?

What will the mountain do next? This was the question uppermost in people’s minds in that area in the weeks following the explosion. By the end of May geologists discovered that a dome was beginning to form in the crater of Mt. St. Helens. Flying over the crater they saw “churning, glowing” molten rock forming this dome. However, later eruptions have blown up this dome and rained ash over wide areas.

As molten rock is forced upward and stacks up, the top cools and this new material pushes up and sideways to form a dome. Such lava domes often increase the height of a mountain. In 1957 a mountain in eastern Siberia erupted and thereafter a lava dome was formed that rose nearly a thousand feet in one year.

Will Mt. St. Helens ever erupt with spectacular lava flows down its sides, as the Hawaiian volcanoes do? The geologists say that’s not possible. The volcanoes in the Cascade range of mountains​—Mt. St. Helens’ location​—have molten rock that is thicker and cannot flow in that way. Just as a spilled milk shake does not run like water, so the molten rock in Mt. St. Helens will not flow down hillsides like the lava of the Hawaiian volcanoes.

Mt. St. Helens could keep spouting off, hurling up rock and ash, for the next 30 years.

Certainly that beautiful and majestic mountain that once enthralled tourists lost much of her appeal when she blew her top. Once 9,677 feet high, she now is some 1,300 feet lower down. Will she make a comeback as some future lava dome builds up? Only time will tell.

[Footnotes]

[Box on page 15]

CASUALTY LIST OF WILDLIFE

5,250 ROOSEVELT ELK

6,000 BLACK-TAILED DEER

200 BLACK BEARS

100 MOUNTAIN GOATS

15 MOUNTAIN LIONS

441,000 SALMON, STEELHEAD AND OTHER TROUT

1.5 MILLION BIRDS AND SMALL MAMMALS

The numbers seem unbelievable, but not when you realize that the blast blew a cubic mile of earth off the top of Mt. St. Helens. Ten miles from the crater the blast hurled a 10-ton Caterpillar bulldozer 1,100 feet through the air. Biologists have called this the greatest natural wildlife disaster in American history.

Many animals were killed at the time of the explosion, but many of the losses will be long term. Animals at the edge of the blast zone survived and moved into adjoining green areas, which will overload those areas and result in starvation.

Three hundred miles of salmon and trout streams and 26 lakes were heavily damaged. In addition, 11 million fingerling coho and Chinook salmon were lost when the Toutle River hatchery was flooded by ash- and mud-laden water.

After examining surviving trout in some streams, game department biologists said: “See those nicks and jagged edges, and the pale coloration? The ash is cutting up their gills. They’ll never make it.”

Ash fallout in the Columbia basin, 100 miles away, showed pheasant nest desertion rates of up to 90 percent. Desertion rates for waterfowl nests at Moses Lake, in the same area, were in the 85 percent to 90 percent range.

An encouraging note: deer have been spotted in the blast zone, eating new vegetation that is growing up through the ash. Game biologist Rich Poelker found good signs of forage returning, young plants growing through the ash. He said: “I see lots of ants, but no other insects. And I haven’t seen nor heard any birds.” His final comment: “I guess you could sum it all up by saying that it will take a long, long time, but the birds will sing again on Mt. St. Helens.”

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