It has been well known for some years that Yellowstone National park, one of the biggest national tourist attractions in America, is the result of a giant supervolcano. A supervolcano is a type of volcano that, as it's name suggests, dwarfs all others. Supervolcanos build up huge reservoirs of magma over hundreds of thousands of years, then release it all in an enormus supereruption. Supereruptions spread ash over thousands of miles and can plunge the entire earth into a mini-ice age that can last a THOUSAND YEARS! Not only does Yellowstone rest on a supervolcano, but this supervolcano is one of the most powerful ones on earth.
And one more thing.
The eruption.
It's overdue.
The last Yellowstone eruption was 640,000 years ago.
Yellowstone is on a cycle of about 600,000 years between eruptions.
Have I sufficiently scared you yet? Good. Now I can get to the real discovery: It seems that the Yellowstone magma chamber is bigger than previously thought. New studies using electrical conductivity have given us this image
I can't be certain, but I think that red stuff is the magma. All that red stuff. I don't mean to sound alarmist, but this is sort of scary. If this chamber empties during an eruption, you could get much of north america uninhabitable, with millions of deaths. That's right, MILLIONS. Volcanic ash stops vehicle engines, and worse, chokes people to death. The ash enters your lungs and reacts with the moisture inside, creating a cement-like substance, which chokes you to death.
Fortunately, an eruption would almost certain be forecasted by scientists months, if not years, in advance. However, one might wonder what would happen to America if we found out that a supereruption was imminent. The law might break down. People might start rioting. The docks and airways would be full of people, wanting to get out before the supervolcanic apocalypse came.
If you really want to know what would happen if a supereruption occurred, try the BBC nonfiction movie Supervolcano.
Sources:
http://news.yahoo.com/s/livescience/20110411/sc_livescience/yellowstonesupervolcanobiggerthanthought
http://www.bbc.co.uk/news/science-environment-13061779
Additional Reading:
Supervolcano, a docufiction movie by the BBC and the Discovery Channel
Mystery of the Megaeruption, a PBS Nova episode about supervolcanos, primarily the one under Lake Toba.
