Photographer: United States Geological Survey
Source: Wikimedia Commons
One of the most powerful and certainly the most disastrous volcanic eruption in American history, Mount St. Helens exploded on the morning of May 18, 1980, killing 57 people and destroying the surrounding area.
The eruption was the culmination of about three months of increasing volcanic activity. Earthquakes and magma reaching the surface of the volcano had created a large bulge on the mountain's side. On May 18, an earthquake caused this bulge to collapse - the largest landslide ever recorded - and an eruption column burst 80,000 feet into the sky. The pyroclastic flow from the volcano reached gigantic speeds, as fast as 670 mph (1,080 km/h), and quite possibly breaking the sound barrier.
Ash was deposited in 11 states. Several people, including 83-year-old innkeeper Harry R. Truman who ran a lodge near the volcano, were killed, and more than $1 billion in damage was incurred.
- 1980-03-27 Mount St Helens becomes active after 123 years
- 1980-05-18 Mount St Helens erupts in Washington state, causing the largest landslide in history, killing 57 people and costing $1 billion in damage