The Yellowstone Caldera supervolcano last erupted 70,000 years ago but a spike in seismic activity around the national park has unsettled nerves. If the Wyoming volcano were to erupt it would kill an estimated 87,000 people immediately and make two-thirds of the USA immediately uninhabitable. The as the large spew of ash into the atmosphere would block out sunlight and directly affect life beneath it creating a “nuclear winter” and threatening ALL life on earth.