A movie comparing what Mt. St. Helens looked like before and after it erupted
| This is a movie of Mt. St. Helens, a volcano in Washington State that erupted at 8:32 a.m. on May 18, 1980. Before it erupted, the mountain was 9677 feet tall. The eruption removed 1314 feet of elevation from the summit, reducing its elevation to the current height of 8363 feet. The resulting crater is over a mile across and 2084 feet deep. An estimated 3.7 billion cubic yards of material was removed from the mountain in the eruption. As you can see from the movie, part of the eruption blast was directed out of the side of the volcano. This lateral blast was composed of 250 million cubic yards of debris traveling at least 300 miles per hour. Twenty-four megatons of thermal and explosive energy were released in the blast.Ê |
Credit: Museums Teaching Planet Earth
For more info: http://vulcan.wr.usgs.gov/Volcanoes/MSH/framework.html