How much ash was there from the May 18, 1980 eruption of Mount St. Helens?
During the 9 hours of vigorous eruptive activity on May 18, 1980, about 540 million tons of ash from Mount St. Helens fell over an area of more than 22,000 square miles (57,000 square kilometers). The total volume of the ash before its compaction by rainfall was about 0.3 cubic mile (1.3 cubic kilometers), equivalent to an area the size of a football field piled about 150 miles (240 kilometers) high with fluffy ash.
Learn more:
- Ash and Tephra Fall Hazards at Mount St. Helens
- Ash Cloud Simulations - What if Mount St. Helens produced an explosive eruption today?
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Pre-1980 eruptive history of Mount St. Helens, Washington
Mount St. Helens erupts again: Activity from September 2004 through March 2005
Eruptions of Mount St. Helens : past, present, and future
Mount St. Helens - From the 1980 eruption to 2000
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Road guide to volcanic deposits of Mount St. Helens and vicinity, Washington
The 1980 eruptions of Mount St. Helens, Washington
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Why is it important to monitor volcanoes?
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