There is a “supervolcano” underground in Yellowstone National Park. Experts say there is a magma chamber as large as Los Angeles four miles beneath the earth, waiting to erupt. No one knows when it will erupt but when it does, it will be a thousand times more powerful than Mount St. Helens. It has erupted before, most recently about 640,000 years ago. It has erupted many times before this, some being even more powerful than the most recent. This would have lead to many plant and animal species becoming extinct. When it erupts again, it will spew ash 25 miles into the sky and could make 2/3 of the United States uninhabitable. Scientists have been keeping track of the ground levels since 2004 and say in some areas of the park the ground has risen around 2.8 inches per year. This is due to the magma chamber “swelling” and could mean the eruption might happen sooner than we thought.