Activity Discovered at Yellowstone Supervolcano

One of the largest supervolcanoes in the world lies beneath Yellowstone National Park and scientists say activity there is increasing.

Though the Yellowstone system, which spans parts of Wyoming, Montana and Idaho, is active and expected to eventually blow its top, scientists don't think it will erupt any time soon. Supervolcanoes can sleep for centuries or millennia before producing incredibly massive eruptions that can drop ash across an entire continent.

Yet significant activity continues beneath the surface. And the activity has been increasing lately, scientists have discovered. In addition, the nearby Teton Range, in a total surprise, is getting shorter.