37. There are six potentially active supervolcanoes.
A supervolcano is more than a mountain with the potential to spew fire and ash into the atmosphere. It is a massive landform that, were it to erupt, could bring human civilization – and potentially all life on Earth – to its knees. Supervolcanoes have a “Volcanic Explosivity Index” or VEI of 8, which is the largest recorded value on the index. The most famous and possibly most heavily studied supervolcano is the Yellowstone National Park. Yes, the entire park is a volcano. There are no volcanoes inside the park; the park is the volcano! These monsters erupt about every 100,000 years, and scientists are concerned that the Earth may be due for another supervolcano eruption soon.
Supervolcanoes are created when magma rises into the crust but doesn’t breakthrough. The pressure builds into a large pool of magma until the crust cannot hold it any longer. Any supervolcano eruption can trigger long-term climate change effects – think Ice Age – and can lead to the extinction of a species or several of them. The most recent supervolcano eruption was when the Taupo Volcano exploded 26,500 years ago. The word “megacaldera” sometimes refers to a caldera supervolcano, like the Blake River Megacaldera Complex in Canada. What a tongue twister; try saying that ten times fast!