Tuesday, June 05, 2007

No Such Thing as Being Safe

"It's a dangerous business going out of your door." --Bilbo Baggins How was your vacation? Pretty good, I reply. We didn't have to use the the tsunami evacuation signs. We didn't feel any earthquakes and the volcanoes did not erupt creating landslides, mudflows and pyroclastic clouds. I must admit to looking over my shoulder at the volcano the entire time we were there, wondering if today would be the day it erupted again. It rained a bit two days, but you expect that in the Pacific Northwest. That's why they have rain forests. In spite of being afraid of heights, I managed not to panic over descending the mountains we drove up, and we only got a little turned around once while driving, not really lost.

We tend to think of life as being safe and ordered most of the time, and instead, we are just really, really lucky. Our visit to Mt. St. Helens National Volcanic Monument emphasized how quickly life can turn completely upside down. 27 years after the eruption, this volcano seems a peaceful place, but the evidence of absolute destruction is everywhere. The horseshoe shape of the crater can be seen from satellite pictures, along with the snow covered peaks of neighboring volcanoes Mt. Rainier and Mt. Adams. This picture is taken from the Johnston Ridge Observatory, five miles away, and the devastation is still everywhere. If you click to view an enlarged version, you can still see a plume of steam rising from the lava dome.

The ranger talks to visitors made it very clear. If you are in the path of an eruption, you will suffocate or bake to death, even if you go to a shelter. There's nothing you can do about it. Debris traveled down the Toutle River, carrying a wall of mud, trees and rocks at speeds of 110-115 miles per hour, endangering the I-5 bridge many miles downstream and filling the valley up to 150 feet. The lateral blast, traveling at up to 670 miles per hour, quickly over took the initial landslide, affecting land up to 19 miles away. The sound of the explosion, however, was not heard locally, but only by those at a distance, strangely enough. Those 57 persons who died mostly suffocated in the hot ash. Two weeks after the eruption, scientists measured the pyroclastic deposits at temperatures of over 600 degrees, so they were much higher when actively flowing. Click to see the amazing pictures of the initial minutes of the eruption.

As volcanic eruptions go, Mt. St. Helens was moderate in size, but compared to other volcanoes in the Cascades range, it is much more active. The damage was from land and mudslides, rock and ash. Any lava that actually flowed was the consistency of toothpaste, we were told, unlike the Hawaiian volcanoes. This eruption was unique in that it has been closely studied by modern scientists. Past eruptions of this and other volcanoes were in non-populated areas, or in a time when people just ran for their lives instead of watching to see what happened. In addition to the eruption itself, scientists have explored the recovery of the area in different ways. Timber companies, such as Weyerhauser, experimented with replacing trees which had been destroyed, which I appreciate since the hills are green again, even if the trees aren't all that tall. In the protected areas, scientists are letting nature take its course to see what happens, and have been amazed at the speed of the recovery. Spirit Lake was completely sterilized and filled with dead trees, mud and ash. Yet in no more than 3 years, bacteria were bringing the lake back to be supportive of life, and within 5 years they were almost back at pre-eruption levels for the water chemistry. Plants and animals moved back in faster than anyone anticipated.

27 years seems like a long time, but geologically, it is only the merest fraction of a blink of an eye. Mother Nature will take all the time she needs to restore this area. The question is, when will this volcano, or any other in the Cascades range erupt again? When Mt. Rainier blew the last time, its flow went all the way into Puget Sound. It is so surprising to a Kentuckian like me, to be able to see three snow covered volcanoes while standing in one spot. The area is active. There ain't no place safe.

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