Supervolcanoes are volcanoes that erupt more than 1000 cubic kilometers of material, making them incredibly dangerous. It’s debated as to why supervolcanoes erupt, but a popular theory is that large magma chambers in the volcano erupt all at once. An eruption like this creates a huge hold called a caldera, which the surface collapses into.
A supervolcanic eruption can have devastating consequences. Ash from the eruption can block sunlight, massively dropping temperatures and harming plant life due to the fact that plants are unable to use photosynthesis. Eruptions like this have led to mass extinctions in the past.