Mt.Saint Helens

Mount Saint Helens



Mount Saint Helens, A volcanic peak in the Cascade Range, Mount St. Helens is
situated in southwestern Washington State. Dormant since 1857, it erupted on May
18, 1980, in one of the most violent volcanic eruptions ever recorded in North
America.

An explosive steam eruption on March 27, 1980, was followed by alternating
periods of inactivity and minor eruption. A severe earthquake on May 18 opened a
crack along the mountain\'s north side. The north slope fell away in an avalanche
that was followed by a lateral air blast that carried hot gases, ash, and stone
outward more than 12 from the summit. Landslides and magma flow flattened
surrounding forests and carried debris as far as 17 miles away.

The blast reduced the volcano\'s height by about 1,300 feet. A second major
eruption occurred on May 25, and magma formed a volcanic dome in the resulting
crater. The eruptions caused more than 30 deaths. After another eruption in
April 1981, experts expected that the volcano would remain active for some where
around 20 years.



Mount St. Helens National Volcanic Monument covers about 110,000 acres. It is
illegal for people to plant trees within these 110, 000 acres. Areas outside of
the monument, however, have been replanted with trees.

Category: Science