Mt. St. Helen

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  • Topic: Volcano, 1980 eruption of Mount St. Helens, Earthquake
  • Pages : 2 (821 words )
  • Download(s) : 204
  • Published : January 30, 2011
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Mount St. Helen is a very active volcano classified as a stratovolcano, stratovolcano is basically a tall volcano built up of layer after layer of hard lava, tephra, pumice, and volcanic ash. Mount St. Helens location is in Skamania County in Washington, with coordinates of 46 12'00.17"N122 11'21.13"W. Mount St Helen is famous because of its catastrophic eruption on May eighteenth in nineteen eighty. The eruption measured a five on the volcanic explosivity index. This is an index created by Chris Newell and Steven Self in the year nineteen eighty-two it was designed to try and measure the explosiveness of volcano eruptions to determine the value of the explosivity and qualitative observations ranging from zero to eight, eight being the most powerful eruption. The eruption that took place on May eighteenth claimed unfortunately the lives of fifty-seven people, two hundred and fifty homes, forty-seven bridges, railways, highways, animals, created a crater on its north side, and ash in eleven states. Following the eruption a massive debris avalanche was triggered by an earthquake which it itself rated a five point zero on the Richter scale. This earthquake was said to have happened because of the surge of magma from the earths mantle. At once the volcanoes elevation was nine thousand six hundred and seventy-seven feet quickly became eight thousand three hundred and sixty-five feet where it is still currently at. Since this eruption Mt. St. Helens has been quiet until a hot spot exploded on July tenth two thousand eight which has since been the last volcanic activity. Some of the other facts this research included on the mountain are how it is rather young, forming within the past four hundred years. Prior to its major eruption in May the volcano was the fifth largest peak rising five thousand feet. The snow that gives this large beautiful volcano its beautifulness packs itself up to sixteen feet. St. Helen started growing in the Pleistocene during Ape Canyon stage....
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