Super Volcano: The Ticking Time Bomb Beneath Yellowstone National Park

Despite growing evidence of geothermic activity under America's first and foremost national park, it took geologists a long time to realize that there was actually a volcano beneath Yellowstone. And then, why couldn't they find the caldera or crater? Because, as an aerial photograph finally revealed, the caldera is 45 miles wide, encompassing all of Yellowstone. What will happen, in human terms, when it erupts?

Greg Breining explores the shocking answer to this question and others in a …