BBC had a news article talking about a possible super volcano and that more activity is happening at the yellowstone national park in the united states. If you don't know what a super volcano is then you should visit the wikipedia page that says there are 7 known super volcanoes.
http://en.wikipedia.org/wiki/Supervolcano
Well many documentaries have been made in the past 10 years to talk about Yellowstone being the next super volcano and that it occurs once every 650,000 to 700,000 years and it hasn't gone off in 630,000 years. If one does go off it seems it will wipe out most of the animals living in north america.
