There have been several write-ups recently about the discovery of another super-sized magma chamber under Yellowstone's other super-size magma chamber, but I hadn't seen it mentioned here. The thing about the second chamber is that it is truly huge--it contains enough magma to fill the entire Grand Canyon to the brim. Eleven times over. Obviously it's been there for a while, so us finding it won't necessarily make Yellowstone erupt any sooner--but when it does, it's probably going to be pretty close to an Extinction Level Event. So pack a few extra bags of Twinkies and yer poncho. It's a hard rain gonna fall.