Saint Helens, Mount, active
volcano, southwestern Washington, in the Cascade Range. The volcano, which had
been dormant since 1857, began to show signs of renewed activity in early 1980
when a column of magma began pushing up inside the mountain, causing the north
face of the mountain to bulge out. On May 18, 1980, an earthquake caused a
landslide on the mountain’s north face, taking off the top of the mountain. The
landslide triggered the main eruption by “uncorking” the column of magma that
had been building up. The eruption spewed a cloud of ash and gases as high as 19
km (12 mi). The blast killed 57 people and damaged life in an area of some 180
sq km (some 70 sq mi), and a vast area was covered with ash and debris. As a
result of the eruption, the mountain's elevation was decreased from 2,950 m
(9,677 ft) to 2,550 m (8,365 ft). A minor eruption occurred in 1982, and the
last magma-producing eruption was in 1986. The Mount Saint Helens National
Volcanic Monument was established there in 1983.
volcano, southwestern Washington, in the Cascade Range. The volcano, which had
been dormant since 1857, began to show signs of renewed activity in early 1980
when a column of magma began pushing up inside the mountain, causing the north
face of the mountain to bulge out. On May 18, 1980, an earthquake caused a
landslide on the mountain’s north face, taking off the top of the mountain. The
landslide triggered the main eruption by “uncorking” the column of magma that
had been building up. The eruption spewed a cloud of ash and gases as high as 19
km (12 mi). The blast killed 57 people and damaged life in an area of some 180
sq km (some 70 sq mi), and a vast area was covered with ash and debris. As a
result of the eruption, the mountain's elevation was decreased from 2,950 m
(9,677 ft) to 2,550 m (8,365 ft). A minor eruption occurred in 1982, and the
last magma-producing eruption was in 1986. The Mount Saint Helens National
Volcanic Monument was established there in 1983.
1 comment:
Hi ElTex ......here's another history page made by a resident of the area around Mt St Helens,......there are some good pictures of the Mtn. before & After..... click on this link to check it out ... http://www.olywa.net/radu/valerie/StHelens.html hope you find it interesting........
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