The most recent super volcano to erupt was Toba 74,000 years ago in Sumatra. Ten thousands times bigger than Mt St Helens, it created a global catastrophe dramatically affecting life on Earth.
It is little known that lying underneath one of America's areas of outstanding natural beauty - Yellowstone Park - is one of the largest super volcanoes in the world. Scientists have revealed that it has been on a regular eruption cycle of 600,000 years. The last eruption was 640,000 years ago…so the next is overdue.