If you’re planning to visit Yellowstone National Park this Labor Day weekend, I have good news: It is very, very, very unlikely that the supervolcano beneath it will erupt while you’re there.
The Yellowstone supervolcano — an 8 out of 8 on the Volcanic Explosivity Index — has erupted three times over the past 2.1 million years, most recently 640,000 years ago. A Yellowstone eruption would be like nothing humanity has ever experienced.
First would come increasingly intense earthquakes, a sign that magma beneath Yellowstone was rushing toward the surface. Then magma would burst through the ground in a titanic eruption, discharging the toxic innards of the earth to the air. It would continue for days, burying Yellowstone in lava within a 40-mile radius.