The Mountain That Roared

On March 20, 1980, a little-noticed earthquake signaled Mount St. Helens first stirrings in 123 years.

Prelude: March 20 to May 17, 1980
by Bill Stewart, Columbian staff writer

It started with a shiver that was felt only in a tiny corner of the woods not far from Clark County. Like an actress building to a dramatic scene, Mount St. Helens marched through a series of activity plateaus. The play is not over, and as officials try to count the dead and assess the damage, nature is mulling over the next act.

Thus far, each new plateau has eclipsed the previous one in magnitude and sheer energy. Disbeliever's found that the warnings of scientists were more than horrible fiction stories dreamed up to scare but not hurt.

SHIVERS: The first chapter of drama started March 20: A relatively light earthquake was the first sign of activity. The quake measuring 4.1 on the Richter scale was localized and not felt by people away from the peak. There was a single seismic station on the west side near the treeline which announced the arrival of a new Mount St. Helens-except no one realized it.

But that Friday's quake was followed by additional activity Saturday March 21, and even more on Sunday. None was very strong, but seismologists were interested.

The activity grew daily. The faster the mountain shook the faster the University of Washington and the U.S. Geological Survey rushed to install earthquake metering device. Most earthquakes were in the range from 3.0 to 4.0 and were limited to the peak and its north slope.

Scientist began to suggest something volcanic might be happening, but the first instrumentation was not complete enough to diagnose the peak's case of indigestion. As a precaution primarily against quake triggered avalanches, the peak was closed to the public March 23.

On March 24, the quake activity, primarily of the much smaller shakes grew so much that the instruments became unreadable. The quakes overlapped. But the area where the shaking was felt continued to be restricted to the Spirit Lake area and on the peak.

ERUPTION: Shortly after noon on Thursday March 27, the mountain started Act 2. An explosion heard in many areas of Clark County spooked already nervous residents of northern communities. It was cloudy and no one could see anything from the ground.

But a news team from The Columbian after circling the cloud-shrouded cap for almost three hours finally was rewarded: There was a hole in the snow near the false summit on the north part of the peak. The pristine snow was smudged with black ash encircling the roundish hole and fanning out eastward. The top especially, the north side, was shattered. Large fissures later measured at mote than a mile long, wound down and to the troubled north side.

The hole was about 200 feet across and 100 feet deep. With the new activity a number of residents from near Spirit Lake moved out. Some of those later moved back again after the mountain's eruption became routine. Earthquake frequency was consistent, although there were a few days in which the number would be higher or lower.

ASH: The mountain started slow, with brief pulses of steam and occasional ash. Much of the time the peak hid in spring weather, but every time the clouds parted, the mountain had turned a little darker. Seismic activity grew in intensity and frequency.

Scientist warned of mud and ash flow. In fact they warned so often that the threats became routine, and soon people began to disbelieve.

Ash began to pour out of the peak regularly, dusting the Northwest with a light coating of gray. A second crater formed on the peak. Eventually that merged with the first one to form pit seven football fields long and about two deep.

When the press hounded scientists for lava, the mountain responded with a blue flame visible only from the air at night. But no lava.

Good weather brought out hundreds of planes buzzing the peak like angry bees. Despite a closure to the general public, the airspace was jammed because most claimed to represent some press outlet. The five-mile limit around the peak shrank and shrank, until it appeared that there was a competition to see who could get the closest. Some people actually landed on the crater rim and climbed inside.

One crew of climbers used camouflaged clothing as they made it to the top-and filmed tow beer commercials. Ash eruptions got stronger, quakes more frequent and scientist competed to see who could up with the best theory about a bigger show.

Then on April 3 came the first "harmonic tremors," indications that lava is moving somewhere inside the mountain. Where normal earthquakes are sharp, abrupt movements, a harmonic tremor came and went at odd intervals. Still no lava.

As the situation seemed to worsen April 4, roadblocks moved spectators farther away from the peak. That prompted all sorts of complaints from businesses, loggers and spectators.

RESTING: On April 22 the mountain refused to spurt. The quakes continued, but the mountain was not erupting. During the following few days, the volcano was down right boring for spectators-after all what can be seen of an earthquake.

BULGE: Someone looked up at the north slope April 30 and said the mountain was bulging. That was prophetically proclaimed as "the most serious potential hazard posed by current volcanic activity."

Scientists determined that the bulge of ice rock was moving northwestward at a rate of five feet per day with little variation. They warned that the danger was that the slope would overextend itself and shear off. The bulge, about two miles around the slope would and 0.6 miles vertically, was to slide down the north slope into Spirit Lake, triggering a large tidal wave of water and mud.

On May 7, with the bulge still growing, the peak erupted with ash again. Quakes continued to strengthen, with the top reaching 5.0. Warnings got louder, and the governor order a strict closure of the peak, admitting only scientist to the inner "red" zone. The outer "blue" zone was restricted to day use, and only a few people qualified roads to circumvent the padlocked roadblocks.

Several new steam vents appeared, as did "hotspots" as the mountain continued to shed its now blackened snow. The crater continued to grow, and when it reached the edge of the top, it started eating down the sides. The false summit was consumed first, and then the marching pit started to nibble southward into the true summit. Still the bulge swelled. More warnings.

On May 12, an earthquake of 5.0 snapped loose an avalanche on the north side. Scientists measuring the bulge looked up at an overhanging wall of ice and decided it was time to move back to a safer vantage-point. That avalanche did not reach Spirit Lake, though where 83-year-old Harry R. Truman was refusing to leave his Mount St. Helens Lodge.

With the blister of ice moving with two newly formed peaks at its crest, the volcano continued to spew ash, steam and an occasional chunk of rock or ice. Quakes did not exceed 5.0 level, but the stronger tremors grew more frequent. Still it was another plateau.

Scientist warned; residents watched; and everyone wondered what the mountain would do next. They did not have long to wait.