The zone was based on a presumption that any eruption would go straight up through the summit. Harry Truman, who owned the Mount St. Helens Lodge on Spirit Lake near the mountain, refused to move ...

For many, the word “eruption” brings to mind 1980 when Mount Saint Helens demonstrated that the Washington Cascades are one of the most volcanically active parts of the country. Mount Saint ...

Feliks Banel remembers where he was when President Jimmy Carter visited the Pacific Northwest following the devastation of the Mt. St. Helens eruption in May 1980. Feliks shared the story on ...

It was larger than any volcanic eruption in the previous 28 million years and hundreds to thousands of times larger than later eruptions such as Tambora, Krakatau, and Mount Saint Helens.

To compare, Mt. St. Helens' eruption in 1980 was a level 4. Known as a super eruption for its magnitude, the event emptied out enough volcanic material to produce the 30-by-40-mile-wide caldera.

The Yellowstone Caldera formed over 600,000 years ago from the Lava Creek Tuff eruption, which was measured on the Volcanic Explosivity Index as an 8, according to the U.S. Geological Survey – the ...

It’s known as a super-eruption because it released an estimated 250 cubic miles of material – 1,000 times larger than the Mount St. Helens eruption in Washington state in 1980. For now ...