A supervolcano is any volcano capable of producing a volcanic eruption with an ejecta mass greater than 10 kg (10 t). Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through the crust, and pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. This can occur at hotspots (for example, Yellowstone Caldera) or at convergent plate boundaries (for example, Toba).