Supervolcanoes

Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure and bursts. A volcano is categorized as a supervolcano if it can produce a magnitude-eight eruption on the Volcanic Explosivity Index, discharging more than 1,000 cubic kilometers of material. A supervolcanic eruption occurs somewhere in the world approximately every 50,000 years. There are about 40 known supervolcanoes around the world, most of which are extinct. If a supervolcano erupts it would have regional effects such as falling ash and short- term changes to global climate.