Mount St. Helens Facts
Mount St. Helens Facts
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Interesting Mount St. Helens Facts: |
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Mount St. Helen's is considered to be the most active volcano in the Cascades for the past 4000 years. |
In March of 1980 researchers at the University of Washington began to get readings on their seismographs hinting of earthquake activity. |
A 4.2 magnitude earthquake was recorded on March 20th, beginning a watch for further activity 24 hours a day. |
On March 27th, 1980 a Hazard Watch was issued by the U.S Geological Survey at 8am. By noon ash and steam were shooting into the air reaching as high as 6000 feet. |
On May 18th, 1980 at 8:32 a.m. Mount St. Helens erupted. The eruption followed a 5.1 magnitude earthquake. |
The volcanologist responsible for reporting on activity of Mount St. Helens, who was camped on top of a ridge in the blast zone at the time of the eruption was David A. Johnston. His last transmission before the blast was "This is it!" He died moments later. |
The eruption began as a landslide. The summit of Mount St. Helens was reduced by 1300 feet. |
The lateral blast that followed the landslide scorched 230 square miles of forest as it blasted at a speed of more than 300 miles per hour down the mountain. |
Volcanic ash rose to more than 80,000 feet into the air within 15 minutes of the landslide. |
The darkness created by the dense cloud of ash turned eastern Washington into night. It became so dark that the streetlights came on automatically. |
The ash cloud from the eruption took only 3 days to cross to the United States' east coast. It took 15 days from the eruption for the ash cloud to encircle the earth. |
The May 18th, 1980 eruption killed 57 people. It destroyed 250 homes, 185 miles of highway, 15 miles of railway, and 47 bridges. |
Mount St. Helens continued to erupt several times in 1980, and although not as explosive as the first, these eruptions sent ash flying to communities in the region. |
Between 1980 and 1986 lava eruptions filled the crater. |
A glacier formed in the crater named Crater Glacier. |
From 2004 until 2008 Mount St. Helens erupted continuously. |
Although the beautiful landscape was destroyed, the lava has left behind a rich and diverse landscape where plants and animals are thriving. |
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