Yellowstone volcano: 'Super-eruption' predicted by expert

When the Germanvolcano last erupted 12,900 years ago, the blast spewed a plume of ash and gasses up to 21 miles (35km) high. The initial eruption would have levelled trees up to 2.5 miles away, followed by weeks or months of activity that covered the surrounding valleys with ash and fallout. Geologists estimate plant life and animals up to 37 miles from the blast were exterminated - a result of the eruption reaching a Volcanic Explosivity Index (VEI) of 6.