A supervolcano is defined as one that erupts with a Volcano Explosivity Index (VEI) of 8 or more, defined as one which releases more than 1000 cubic kilometres of ejecta into the atmosphere. The largest eruptions ever recorded are VEI 8, with the most recent being the Oruanui eruption in New Zealand around 26,500 years ago. Ash from the eruption has been found in ice cores from Western Antarctica, more than 5000 km from the eruption.
