@sauravrungta : nice post - in fact, I was reading this book called A Short History of Nearly Everything by Bill Bryson and he had discussed about volcanic activity and the kind of havoc it can create - akin to what you were mentioning here - another interesting fact was that yellowstone national park is built on an active volcano (active yes - but errupts on an average once in every few hundred thousand years).. and we really don't know when the next one is due.. and when that happens, all hell will break loose in America.