HELENA, MT – The hot molten rock beneath Yellowstone National Park is 2 1/2 times larger than previously estimated, meaning the park's super-volcano has the potential to erupt with a force about 2,000 times the size of Mount St. Helens, according to a new study.
By measuring seismic waves from earthquakes, scientists were able to map the magma chamber underneath the Yellowstone caldera as 55 miles long, lead author Jamie Farrell of the University of Utah said Monday.
The chamber is 18 miles wide and runs at depths from 3 to 9 miles below the earth, he added.
That means there is enough volcanic material below the surface to match the largest of the super-volcano's three eruptions over the last 2.1 million years, Farrell said.
The largest blast -- the volcano's first -- was 2,000 times the size of the 1980 eruption of Mount St. Helens in Washington state. A similar one would spew large amounts of volcanic material in the atmosphere, where it would circle the earth, he said.
"It would be a global event," Farrell said. "There would be a lot of destruction and a lot of impacts around the globe."
"We do believe there will be another eruption, we just don't know when," he said.