Nevada Has a Supervolcano

Fri, 08 Feb 2008 17:25:53 GMT

clipped by: dmegivern

Nevada Supervolcano's Flesh Exposed

Feb. 7, 2008 -- The fault-riddled landscape of northern Nevada has sliced and diced the remains of one of the world's largest volcanoes, providing a rare chance to inspect the innards of the so-called "supervolcano."

The Caetano caldera was a 12-mile-wide crater after it erupted 33.8 million years ago and sent a catastrophic ejection of more than 270 cubic miles of molten, lathered rock into the air.

The Caetano caldera is not related to the Yellowstone eruption, but both were caused by a gigantic plume of hot rock moving up through the crust. Calderas like these are so large that they can't erupt through a single opening, like most volcanoes. Instead, a caldera ejects molten material and gas in a ringed fracture zone.

The land in the center of the ring, which acts like a lid on the huge pool of magma, collapses. The collapsing lid provides even more oomph to the explosion of hot, foaming magma out of the ring of fractures.

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Nevada Has a Supervolcano

Nevada Supervolcano's Flesh Exposed