The molten rock hiding beneath the Yellowstone National Park is approximately 2 ½ times larger than researchers thought it was.
Scientists mapped out the size of the giant magma chamber under the park, and determined it was 55 miles long, the Associated Press reported. The chamber also stretches three to nine miles below the Earth's surface and is about 18 miles wide.
"We've been working there for a long time, and we've always thought it would be bigger... but this finding is astounding," Professor Bob Smith, of the University of Utah, told the BBC.
This finding indicates there is enough magma stored up to feed a repeat of one of the three of the supervolcano's past eruptions that have occurred over the last 2.1 million years, the AP reported.
If a blast were to occur it would be devastating. The eruption would be about 2,000 times the size of the Mt. Saint Helen blast that took place in 1980.
"It would be a global event," lead author Jamie Farrell of the University of Utah, told the AP. "There would be a lot of destruction and a lot of impacts around the globe."
The last Yellowstone eruption took place 640,000 years ago, and researchers believe the supervolcano is "overdue" for another one.
If the volcano did erupt, it could send a behemoth plume of ash all the way around the world; this also occurred during the last eruption thousands of years ago.
While researchers are concerned about the festering volcano, they believe an earthquake in the region is more imminent.
"It helps us understand the active system," Brigham Young University geology professor Eric Christiansen said. "It's not at the point where we need to worry about an imminent eruption, but every piece of information we have will prepare us for that eventuality."
The Italian volcano Mt. Etna recently erupted, causing an airport to shut down.
