Week 4 - Mount St. Helens

Credit: National Geographic

Mount St. Helens, located in the rain-laden Pacific northwest in Washington State, was always a mystery to me as a child because its eruption was still very real to my parents during my childhood. I jumped at the chance for a field trip to the mountain going through grade school. Noted as one of the most active volcanoes in the US by National Geographic, Mount St. Helens last eruption occurred in 1980. The event killed 57 people and flattened more than 518 sq. km. (nearly 200 square miles) of forest around the volcano (National Geographic, 2010).

I remember as a child that the trek by car to the mountain was eerily fun because we went in the late 80s and early 90s. The landscape was much different than what you’d see today nearly 40 years later. The forests which dotted the landscape were nearly wiped out, but those that remains were charred and blasted stumps. Volcanic and other sediment clogged many of the rivers which left the geography completely altered compared to before its eruption.

Credit: USGS

The eruption of Mount St Helens was classified as a “Plinian” type eruption (USGS) which are among the most violent and powerful eruptions that occur. The resulting eruption sent ash into neighboring states, as my parents who lived in Oregon at the time, pointed out to me during our drive into Washington. What did this mean at the time for them? Being in Oregon, it was a relatively minor inconvenience, but it was quite dangerous for nearby observers and residents. Rock and superheated gas blanketed the northern area of the mountain after an initial earthquake revealed the volcanic dome before it’s eruption in 1980. The gas and ash blanketed the skies until it finally erupted, where the eruption itself was equated to roughly 15 atomic bombs that were dropped in Hiroshima.

The mountain is still monitored today for volcanic activity and, as of 2012, it was on the list as the 2nd most dangerous volcano in the United States. If it were to erupt again, an ash plume could reach up to 30,000 feet and blanket the Pacific northwest in ash and other sediment in as little as 5 minutes.  The renewed glaciers atop the mountain could also devastate the ecosystems for the valleys surrounding the mountain as runoff carries debris and ash into them.