A supervolcano is a volcano that has had an eruption with a volcanic
explosivity index (VEI) of 8, the largest recorded value on the index.
This means the volume of deposits for such an eruption is greater than
1,000 cubic kilometers (240 cubic miles).
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 ruptures.
There are 8 locations: