National Geographic : 2009 Aug
Fire and debris spew from Yellowstone in an artist's depiction of a supervolcanic eruption. It's unlikely the next major blast will occur in our lifetimes, but scientists have their ears to the ground. When Yellowstone Beneath Yellowstone Park a monstrous plume of hot rock is causing the earth to heave and tremble. Past volcanoes have erupted with a thousand times the power of Mount St. Helens. The future is anybody's guess.