[MattinNJ]

Wow. Sobering. I remember reading in one of Bill Bryson's books that Yellowstone is a giant volcano and could eventually wipe out mankind.

[Riley]

http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml

Interesting BBC piece (with transcript) on the Yellowstone supervolcano. I'm no vulcanologist, but my read is that there's enough potential energy there to put an all-out nuclear exchange to shame.

[blam]

"I remember reading in one of Bill Bryson's books that Yellowstone is a giant volcano and could eventually wipe out mankind."

It's on a 600,000 year cycle and is presently 40,000 years overdue. Recently, portions of Yellowstone have been sectioned off (no public access) because of extreme temperature increases not seen before.

[dljordan]

It's an ancient caldera about 30 miles across I think. It's been bulging upwards over the last few years and the ground there has gotten up to 200 degress in some places. It won't wipe out the world though, only the surrounding states. Nebraska will be under several feet of ash. Not to worry.

[NotJustAnotherPrettyFace]

I just watched a documentary on the Yellowstone caldera the other night, and yes, the Toba "blast" which created a "volcanic winter" was mentioned as a possible comparison.