Science: Mount St. Helens

It is hard to believe that a quarter century has past since I woke up one morning to find my front yard covered in gray ash.  In May 1980, I was living on the Pacific Coast of Washington state enjoying my view of the ocean from my cliff-side home.  However, that morning I has a different scene out the front door of my house, with dark clouds full of ash filled the sky.  It is not often that I live through a major historical moment, and it is definitely one I will never forget.

We all know the story.  For two months in 1980, a series of earthquakes around the volcano signaled that she was waking up.  As pressure increased within the volcano, the North face of the mountain began to expand while steam vented from the cone.  Then in May, a massive earthquake triggered a collapse of the North face, having it slide down the slope, weakening the volcano and triggered the massive explosion which obliterated the top and side of the mountain.  All of this material combined with mud and melting glaciers to flood the nearby rivers, carrying away earth and trees which were displaced by the explosion.  Images like the one below are etched in our minds and complete the story which words can not describe.

 erruption

After a decade of moderate activity and reconstruction, the mountain has awaken again.  Steady earthquake cycles shake the mountain and surrounding areas while slowly rising magma has built a new lava dome.  It is not uncommon to see vapor clouds form above the dome as small steam vents open up to relieve some of the building pressure within the mountain.  And then again, you will have days like today. 

Around noon local time, the mountain gave off a large plume of steam and ash which was caught on camera.  Film crews were near the scene as the ground shook and steam began to rise from the cone.  Fortunately for us, there was a second camera pointed right at the camera when the event occurred.  This camera is mounted a few miles away at the Johnson Ridge Observatory, and streams video live online for everyone to watch the mountain 24 hours a day.  Below is a still image taken from the live cam, showing you how the camera is aimed at the North slope and open crater.  When there is no steam coming from the crater, you can clearly see the new lava dome that has risen in the past two years.

 

The following links are handy if you are interested in tracking Mount St. Helens’ progress:

Mount St. Helens volcanocam

USGS Earthquake tracker

360 degree views of the volcano (2003/2006)

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