New Madrid is a town in southern Missouri with a fault nearby. It isn't well known to the public, but seismologists know it well: 16 Dec 1811: Magnitude 8.6 23 Jan 1812: Magnitude 8.4 7 Feb 1812: Magnitude 8.7 Magnitudes are Richter Scale estimates. For comparison the 1906 San Franciscon quake on the San Andreas was 8.3. So that 8.4 up there is _big_. But not the biggest. The Mississippi ran uphill during some of those shocks, and foot-high waves ran through the ground like surf. Whee!