If the Yosemite supervolcano erupts, what will the effect be on the surrounding area at various distances?

Question

For instance, I assume there would be an incineration crater of some sort where the energy released by the blast vaporizes some of the surrounding area. Then the atmosphere would experience different effects based on distance, though some things would circulate around the globe in even distribution. I also imagine it would produce some ejecta, possibly even launching some of it into orbit.

But these are just my guesses. Does anyone know?

Answer 1

Based on the last big eruption of Yellowstone (about 630,000 years ago with an average of one big eruption every 600,000 years or so), everywhere within about a 1000 KM radius of Yellowstone would be hit the hardest; most Central and Western States, and parts of Canada and Mexico, would be buried in several feet of volcanic ash, though the effects would diminish as you got to the East Coast. The eruption would also probably be followed by years, possibly decades, of volcanic winter.

For a more detailed account of what Yellowstone can do read the chapter dedicated to it in Bill Bryson's A Short History of Nearly Everything.

Answer 2

Don't know anything about a supervolcano at Yosemite, but I saw the Discovery Channel special about a possible Yellowstone supervolcano eruption and the main effect that stuck in my mind is that my home town, Salt Lake City (about 300 miles away) would be turned into Pompei, with over 20 feet of ash covering everything.

Answer 3

There is a supervalcano under Yosemite that could blow up any minute! Between now and 15,000 years from now.  I really wouldn't waste your time worrying about this or the end of the mayan calandar or y2k.  If it happens though, there would be a shockwave that will be felt around the world, followed by a radiation wave then volcanic ash would fill the sky for months (I believe) and most living things on earth would wither and die and our future solar panel houses and cars won't work either - so we better stick with fossil fuels, haha.