United States

Mount St. Helens Eruption

Photo credit: Lyn Topinka

By March, 1980, Mount St. Helens in Washington state in the U.S. Pacific Northwest region hadn’t erupted for over a century. But at the end of that month, hot magma rose to meet with icy meltwater, building up enough pressure to cause an eruption. Scientists were convinced there would be what’s known as a vertical eruption—straight up, causing little danger to residential areas and infrastructure in the mountain’s shadow. But less than two months later, a massive earthquake equivalent to 1,500 atomic bombs, caused the side of the mountain to explode and collapse. More than 1,000 feet of Mount St. Helens disappeared as gas, ash and rocks shot 15 miles up into the air, and a river of slurry began its path of destruction. Fifty-seven people died and hundreds of homes were destroyed in what’s considered the most disastrous volcanic eruption in U.S. history. The photograph shows a 3,000 foot-high plume of steam two years after the 1980 eruption.

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