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Showing posts with label Mt. St. Helens. Show all posts
Showing posts with label Mt. St. Helens. Show all posts

March 3, 2016

Eruption Mt. St. Helens


Eruption volcano Mt. St. HelensOn May 18, 1980, a major volcanic eruption occurred at Mount St. Helens, a volcano located in the state of Washington, United States. The eruption (a VEI 5 event) was the only significant one to occur in the contiguous 48 U.S. states since the 1915 eruption of Lassen Peak in California. The eruption was preceded by a two-month series of earthquakes and steam-venting episodes, caused by an injection of magma at shallow depth below the volcano that created a huge bulge and a fracture system on the mountain's north slope.