Volcanoes like Yellowstone are called 'supervolcanoes', because they are so huge and dangerous-1,000 times more powerful than ordinary volcanoes. There are about 40 of them on Earth,but none of them has erupted recently. There most recent was 74,000 years ago in Indonesia. The last time Yellowstone Park erupted was 640,000 years ago.
But what would happen if the Yellowstone volcano erupted again today? Here are the events that might follow:
Day i-Yellowstone Park,USA