ROCK DOC - Blast at mountain followed by eruption of life

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The time has surely flown by for me.

Thirty years ago I was a very young woman, really just a kid, living downwind of Mount St. Helens on the beautiful Sunday on which she tore herself apart. This was in the days before the Internet and even before 24/7 cable news, so our first clue the mountain had erupted catastrophically was when we were enveloped in a dense and dark ash cloud.

Even us hayseeds knew we were seeing history unfold. Quite likely the personal path that led me to study geology was sketched somewhere in my unconscious mind in the gathering gloom of that day. I suspect that geologic catastrophes are large enough you either run away from them or, if you are perhaps a bit deranged, feel drawn toward them. I've always been in the second camp, wondering what powerful display of mighty forces the Earth will next show us -- and whether we will survive.

But what I remember most clearly about that midday was simply the great challenge of breathing while walking to the safety of home. I breathed through a mitten left over from winter that was jammed in my coat pocket. (In those days, many of us still used mittens made at home by grandmothers. We should have treasured them more than we did.) The loosely knitted mitten didn't help filter the air that much, and the fine ash made it into my nose and mouth and down into my lungs enough to make me cough and hack.

During the past 30 years, there have been, to be sure, some more minor eruptions of steam, ash and lava in the crater left behind by the catastrophic blast.

But there's been another "eruption" at Mount St. Helens in the years since 1980. In ways that many biologists would not have guessed were possible, life itself has erupted in abundance, re-colonizing what was a seemingly barren moonscape left behind the day that had me digging for mittens in my coat pocket.

First in the story of rebirth were the survivors themselves. The month of May around Mount St. Helens is snowy in many areas. So some pocket gophers and deer mice, snuggled into burrows underground and under the snow, survived the great blast. The gophers, in particular, tunneled as they ate their way through roots and bulbs, pushing up good earth through the snow and volcanic ash to the surface -- providing small plots of bedding material for wind-blown seeds to come.

Also buried by snow were small young fir trees, flexible enough they were prone to the ground all winter. Some of them straightened, breaking through the ash layer, and poking above the surface of the moonscape as one of the first signs of how quickly life might return to the mountain.

Then there were the plants and animals that came into the barren zone as colonizers. One of the first was the purple lupine, a fine flowering plant familiar to all alpine hikers. It, and the microorganisms that live with its roots, added nitrogen to the volcanic ash. This helped other plants take root as well. The pocket gophers had more roots and bulbs to eat -- so more pocket gophers lived to breed. Mice and gophers attracted those that eat them: birds of prey and coyotes.

None of this change has been steady. It's been a cycle of boom and bust for many different species. Mother Nature isn't sweet and gentle in her care for creation -- that's a fuzzy myth we carry in our heads sometimes. But nature surely is fertile. That's nowhere more clear than in the large lake that lies at the foot of the mountain, that was once a toxic soup and is now a source of prime nutrients that are spreading to the land around it.

Remember the little evergreens that survived because they were so small they were lying flat under the snows? Today those trees have grown to the point they are producing seeds. They are in the fullness of early adult life (I do so wish I could say the same).

E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human and Natural Resource Sciences at Washington State University. Peters can be reached at epeters@wsu.edu.

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