Few volcanoes on Earth boast the fantastical title of "supervolcano," but what makes these uber volcanoes so super, and is the superlative always justified? It very much depends on who you ask.
A supervolcano is a volcano that has produced at least one supereruption, meaning that at some point in its history, it has ejected more than 240 cubic miles (1,000 cubic kilometers) of volcanic material — enough to fill Sydney Harbour 2,000 times. This scores an 8 on the Volcano Explosivity Index (VEI), a scale that measures the volume of material ejected, as well as the height and intensity of the eruption plume.
