July 16, 2016

"Every 100,000 years or so, somewhere on Earth, a caldera up to 50 kilometers in diameter collapses and violently expels heaps of accumulated magma."

Science: The resulting supervolcano is both unstoppable and ferociously destructive. By Julia Rosen

'One such monster, the massive eruption of Mount Toba in Indonesia 74,000 years ago, may have wiped out most humans on Earth, causing a genetic bottleneck still apparent in our DNA—although the idea is controversial.

'By geological convention, a super-volcano is one that produces an explosive eruption of more than 450 cubic kilometers of magma—roughly 50 times more than the eruption of Indonesia’s Mount Tambora in 1815, and 500 times more than the Philippines’ Mount Pinatubo in 1991. Geologists read the histories of such blasts in deposits of erupted material called tuff, and the rock record shows that super-volcanoes tend to be repeat offenders. Locations that remain active today include Toba, the Yellowstone hot spot in the northwestern United States, the Long Valley Caldera in eastern California, the Taupo Volcanic Zone in New Zealand, and several spots in the Andes.'

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