Sunday, August 25, 2013

Mount St. Helens National Volcanic Monument

This mountain is the youngest and most explosive of the Cascade Mountain volcanoes.  Thirty-five hundred years ago she exploded producing thirteen times more ash and rock than on May 18,1980.  The mountain is about 100 miles northeast from where we are parked here in Portland.  We drove there on Friday, which turned out to be a long trip as it involved a lot of mountainous driving over narrow winding roads which have been damaged by frost heaves.  Unfortunately we never did get a good view of St.Helens because of the heavy cloud cover over her on the day we were there. 
Notice in the picture above grey spots on the hillsides where there are no trees.  In 1980 magma burst from the mountain outward in a hurricane-force blast of hot gas, ash and rock.  In its wake it left a grey patchwork of falling and standing dead trees.  The lateral blast destroyed 230 square miles of forests, most of which lay in Gifford Pinchot National Forest.  Our first stop was at an overlook which gave us a good view of Clearwater Valley.  It lies in the "scorch zone".  Within 2 to 17 miles of St. Helens trees in this area were either scorched or killed.
Thirty-three years ago there would not be the vegetation which we see in the picture above.  Fifty-seven people lost their lives when the eruption occurred, and they were outside of the restricted areas.  On May 15, three days before the blast, a couple left their car and hiked 8 miles to a cabin.  They had signed a state liability waiver so they could be in the "blue zone".  They died, and their 1972 Pontiac is pictured below.
Of course, this car was not a rust bucket when we saw it about 20 years ago!  The blast temperature has been estimated at 400 degrees F. It sandblasted the paint off the car and melted the interior.
Spirit Lake was another of our stops of the day.  The explosive force of the volcano caused a landslide of water sloshing 800 feet up to the adjacent hillsides.  As the waves surged back it swept trees into the lake, many of which are still floating there.  Soon afterwards scientists discovered all visible life was gone from the lake;  bacteria, slime mold, and fungi took residence in its waters.  In five years the lake recovered and by the tenth year the lake was nearly normal again- wind, rain and snow melt helped it to restore.  We hiked down to the lake, and it was interesting to see how the land is now covered with wildflowers and small trees.  After the blast a blanket of pumice and ash 6 to 14 inches deep covered the valley- I wandered off the path once and immediately sunk down a few inches into the grey sand.  It is sad to see all the damage done by volcano, but nature does heal itself.  Interpretive signs at park informed us that downed logs stabilize the shores as well as make ponds for fish habitat.  The pumice keeps moisture in the soil during drought.  Seedlings grow better than at logged sites because there is no vegetation to compete for light and nutrients. Hiking back up the hill from the lake I could not help but appreciate the beauty among the fallen trees.

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