How about the ongoing earthquake swarm at Yellowstone?
Yellowstone is the caldera of a "super volcano", one that has erupted on a roughly 600,000 year cycle, with its last eruption being some 640,000 years ago, so another eruption is most likely due.
If it goes, it will make a man-made nuclear winter look like spring break. This bit from the Discovery Channel website:
The crater atop Mount St. Helens is about 2 square miles. The Yellowstone "caldera" — a depression in the Earth equivalent to a crater top — is some 1,500 square miles.Obama may be in for a hell of a lot more than he ever bargained for.
The 1980 Mount St. Helens eruption blew 1,300 vertical feet off the mountain, sent an eruption column 80,000 feet high in 15 minutes, ejected 1.4 billion cubic yards of ash detectable over 22,000 square miles, and killed 57 people.
But the last major eruption at Yellowstone, some 640,000 years ago, ejected 8,000 times the ash and lava of Mount St. Helens.