A supervolcano is any volcano capable of producing a volcanic eruption with an ejecta mass greater than 10¹⁵ kg. Supervolcanoes can occur when magma in the mantle rises into the crust from a hotspot 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 is the case for the Yellowstone Caldera). They can also form at convergent plate boundaries (for example, Toba). Large igneous provinces can cover huge areas with lava and volcanic ash, causing long-lasting climate change (such as the triggering of a small ice age or global warming), which can threaten species with extinction.