Page Nav

HIDE
TRUE

Breaking News:

latest

Ads Place

Latest

Footage of the 1980 Mount St. Helens Eruption

On May 18, 1980, the Mount St. Helens became the largest and most destructive volcanic eruption in U.S. history. By the end of its cycle...


On May 18, 1980, the Mount St. Helens became the largest and most destructive volcanic eruption in U.S. history. By the end of its cycle of fire and fury, 57 people had died.

The eruption was preceded by a two-month series of earthquakes and steam-venting episodes caused by an injection of magma at shallow depth below the volcano that created a large bulge and a fracture system on the mountain's north slope. An earthquake at 8:32:11 am PDT (UTC−7) on Sunday, May 18, 1980 caused the entire weakened north face to slide away, creating the largest landslide in recorded history. 

This allowed the partly molten rock, rich in high-pressure gas and steam, to suddenly explode northward toward Spirit Lake in a hot mix of lava and pulverized older rock, overtaking the landslide. An eruption column rose 80,000 feet (24 km; 15 mi) into the atmosphere and deposited ash in 11 U.S. states and two Canadian provinces.


No comments