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Mount Saint Helens
mountain, Washington, United States
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External Websites
- LiveScience - Mount St. Helens Eruption: Facts & Information
- San Diego State University - Department of Geological Sciences - Mt. St. Helens Eruption
- Oregon State University - Volcano World - The Eruptive History of Mount St. Helens
- United States Geological Survey - Mount Saint Helens, Washington, United States
Britannica Websites
Articles from Britannica Encyclopedias for elementary and high school students.
Mount Saint Helens, volcanic peak in the Cascade Range, southwestern Washington, U.S. Its eruption on May 18, 1980, was one of the greatest volcanic explosions ever recorded in North America. Mount Saint Helens, named by the English navigator George Vancouver for a British ambassador, had been dormant since 1857. An explosive steam eruption on March 27, 1980, was followed by alternating periods of quiescence and minor eruption. Pressure from rising magma within the volcano caused extensive fissures and the growth of a bulge on the north flank of the peak. On the morning of May 18, an earthquake with a ...(100 of 561 words)