Sometimes, when I am about to write a column on one of my experiences, I am faced with a dilemma: Does this belong in the category “Backroads geology” or in “Awe”?
Over the years, I have written on the geology of the Grand Canyon, the Hawaiian lava flows, Egypt’s Valley of the Kings, and Chaco Canyon in New Mexico — all of them with interesting geology but also inducing awe.
The climb of Mt. St. Helens, which I undertook with a friend some years ago, certainly confronted us with some textbook examples of geologic forces but also exposed us to the power of nature to both destroy and create on a massive scale. And though awe can sometimes reduce a person to silence, in this case our first view of the destructive aftermath resulted in an incongruous Anglo-Saxon expletive. But more of that later.
Prior to May 18, 1980, Mount St. Helens was known as America’s Mount Fuji. A steep-sided peak with its summit eternally snow-covered, it loomed above its surrounding landscape as in a Japanese block print: One could imagine it viewed through the branches of a cherry tree in full bloom under a milky blue sky with a diminutive pagoda as a symbol of the smallness of human constructions compared to those of nature.
But the tranquility of such a scene was illusory. Like Mount Fuji and a number of other dangerous peaks in the Cascade Mountains — Rainier, Mount Hood, and Baker among them — Mount St. Helens is a strato-volcano.
It is composed of layer upon layer of debris blasted out of the earth over millennia in a series of violent eruptions. Beneath the snow-capped peaks of the Cascades lies a subduction zone — a gigantic fault line at which one of Earth’s lithospheric plates is diving under another. The resulting friction causes melting of the rock on a massive scale, which then can rise to the surface and explode with terrifying force.
Explosion
And that is precisely what happened on May 18, 1980 after weeks of increasingly strong tremors and bursts of ash coating the mountain’s snowy summit.
Early that morning, the series of earthquakes that had been giving ample warning of magma on the move through a chamber beneath the mountain produced a major temblor that shook the ground for miles around followed by a gigantic landslide on the north slope.
Anyone who has ever shaken a warm bottle of a carbonated beverage and then loosened the cap could predict what happened next. The instant that the magma in the chamber had access to the vastly lower pressure outside, it exploded with almost unbelievable violence — laterally instead of vertically from the summit as might have been expected.
In a scorching explosion called a pyroclastic surge, three cubic kilometers of the mountain disintegrated and blasted northward at hundreds of miles an hour, destroying great stretches of forest, burying half of pristine Spirit Lake, and killing unknown numbers of wildlife; 67 people unfortunate enough to be hiking or camping in the line of the blast also perished.
In an instant, “America’s Mount Fuji” was turned into an ugly crag with a gigantic gaping crater where its gleaming snow-capped summit had been.
Recovery
And then the mountain went back to the slumber in which it had rested for centuries.
Anyone who has seen the photos of the explosion and subsequent devastation would find it hard to believe that the land north of the mountain could recover in many lifetimes. But volcanic soils are loaded with minerals — those that buried Pompeii are some of the most fertile in Italy — and within a very few years the landscape to the north began to turn green as seedlings and grasses took root and shortly herds of elk were seen grazing in the blasted area.
Scientists and hikers alike were stunned by the ability and swiftness of the recovery even amid the wreck of millions of toppled trees. Within a few years, permits were being issued on a limited basis allowing climbers to ascend the southern slope of the mountain, which was relatively unscathed in the catastrophic blast.
Yet even as hikers made their way through the forested lower sections and across the slender glaciers that stretched down from the heights above timberline, within the raw crater a huge steaming dome of solidified lava showed that St. Helens was slowly rebuilding its summit.
My climbing companion and I had spent the night before our climb in the tiny village of Cougar (population 122) some 13 miles southwest of the mountain. The townspeople had made the most of the fact that visitors to the volcano would pass through the village and souvenir shops had popped up selling postcards, paintings and photographs of St. Helens, DVDs of the event, and pottery made with volcanic dust
It undoubtedly was a sobering thought for the population that, had the mountain’s erratic explosion occurred on its south side, the village and its population would have been obliterated.
Ascent
We began our ascent on a cool morning at the trailhead called “Climbers’ Bivouac,” at an elevation of around 5,500 feet — a starting point higher than any mountain peak in New York state, and the relative thinness of the air was apparent as soon as we set out.
During summer months, the number of climbers was limited to 100 to protect the fragile environment and we had secured our permits some weeks before. The trailhead is surrounded by tall Douglas firs that were relatively untouched by the blast, unlike the devastation on the north side of the mountain.
We had slathered our faces and arms with sunscreen as the sun is intense at high altitudes, especially on such a near-cloudless day as this one. The trail led in a series of switchbacks up through the forest and crossed a series of small brooks trickling down from ice higher up on the mountain.
But we soon noticed something ominous: Instead of the dark, loamy soil one would expect in an old forest, a thick gray layer of ash covered the ground between the trees, residue from the blast.
As we approached timberline, the view suddenly became expansive: snow-capped jagged peaks of the Cascade Mountains against a deep blue sky with a few high, wispy clouds.
Now the slopes above us were covered with angular boulders patterned with lichens of many colors and from their shadows the furry little rodents called pikas were whistling warnings of the intruders to their companions.
We had not seen any other climbers but occasionally we could hear voices from above so we knew we were not the first on the mountain that morning. The temperature was dropping with the altitude and the dryness of the air was making us thirsty so we paused to put on parkas and swig some Gatorade.
The trail then took us through some crusty patches of snow and across the diminutive Shoestring Glacier on which numerous small brooks trickled over the ice under the high sun.
The trail became steeper and because of the increasing thinness of the air — we were nearing 10,000 feet — every step became more exerting. Now we were ascending over slippery volcanic dust; the switchbacks became tighter and steeper and soon high above us was the top of Mount St. Helens.
But there was no peak.
Instead we could see a long, flat ridge and a handful of climbers perched on it. The ascent had taken just about three hours and now the sunlight was intense. Near the top, the trail disappeared into rubble and a scattering of herd paths continued upward. And then we arrived at the rim of the crater and the devastation lay starkly before us.
“Holy s***!”
I don’t remember which one of us said it, but a group of climbers a few dozen feet away eating their lunches burst into laughter. We must have looked at them with very puzzled expressions because one of them said, “Everybody who has come up the trail and taken a look says the same thing!”
We were standing on the rim of the crater from which a layered cloak of ice several feet thick plunged downward over a thousand feet. Like a great rocky amphitheater, the crater opened, and in its center the steaming lava dome — now a couple of hundred feet high — showed that the mountain’s subterranean fires were still very active.
To the north, millions of parallel, charred fallen trees showed the result of the pyroclastic surge that had rushed from the explosion at hundreds of miles per hour, burning everything in its path that it did not bury.
In the far distance, once-pristine Spirit Lake was now half its size and thousands of denuded trees floated like abandoned canoes on its surface along with tons of pumice pebbles — volcanic rocks less dense than water.
The scene quickly evoked silent contemplation, broken only a few minutes later when another party reached the rim and stared for a moment before one of the awestruck climbers said, “Holy s***!”
In real time, it could of course be hundreds of years before Mount St. Helens next erupts and by then the great mossy forests that will surround it may be filled with vast herds of elk and mountain goats and the occasional bear roaming the apparently benign landscape.
But in geologic time that is but the wink of an eye and beneath the mountain the magma will still surge and only the occasional coating of ash on the gleaming snowcap of the mountain will indicate that it is about to awaken from its slumber.
There is no way to predict in which direction the volcano may next unleash its destruction. But St. Helens is only one of the volcanic peaks of the Cascades that could erupt.
Mount Rainier, sitting so near the cities of Seattle and Tacoma, is said to be among the most dangerous, covered as it is in glaciers that would melt in an eruption sending great rivers of suffocating mud behind its pyroclastic surge, burying everything in their paths.
One can only wonder at the human propensity to build our cities in places subject to earthquakes and tsunamis and volcanic eruptions and other geologic hazards. And how ironic that they are often locales of awesome beauty.
