Enormous magma reservoir found under Yellowstone

There's enough magma bubbling in the massive "supervolcano" under Yellowstone National Park to fill the Grand Canyon more than 11 times, scientists reported in a study this week.

"For the first time, we have imaged the continuous volcanic plumbing system under Yellowstone," said study lead author Hsin-Hua Huang of the University of Utah.

The reservoir of hot, partly molten rock is located about 12 to 28 miles beneath the Yellowstone supervolcano. This newly discovered, deep reservoir is in addition to a separate shallower, long-known magma chamber that's about 10 miles underground.

The huge bowl-shaped collapsed volcano — known as a caldera -— in the middle of the park last erupted 640,000 years ago. It's one of several large and still active calderas in the U.S.

If the supervolcano erupted today, the results would be "cataclysmic," said study co-author Robert B. Smith, a University of Utah geologist. Fortunately, the chance is only 1 in 700,000 that we'll see an eruption in any given year, he added.

Researchers emphasize the volcano is no closer to erupting than before. They've just used advanced techniques to make a complete image of what's going on down there.

The study was published Thursday in the journal Science.