Headline in USA Today: "Yellowstone super volcano may blow sooner than thought — and could wipe out life on the planet."
The last eruption of the super volcano underlying all of Yellowstone National Park happened over 630,000 years ago. The Yellowstone caldera is 40 miles across. The entire area has bulged up some ten inches, "an extraordinary uplift," suggesting an enormous build up of pressure from accumulated magma.
When it blows ... well, you can kiss your sweet ass goodbye. "It has the ability to expel more than 1,000 cubic kilometers of rock and ash at once — 2,500 times more material than erupted from Mount St. Helens in 1980, which killed 57 people. That could blanket most of the United States in a thick layer of ash and even plunge the Earth into a volcanic winter" (Shannon Hall).