The New Madrid Seismic Zone
The New Madrid Seismic Zone encompasses parts of Missouri, Arkansas, Tennessee, Kentucky, and Illinois. It is the most active seismic area east of the Rocky Mountains. Between December 1811 and March 1812, a series of earthquakes estimated to be in the 6.5 to 8.0 range struck the area. An earthquake today of that magnitude would be felt in Kansas City and cause widespread damage in St. Louis and Memphis.
New Madrid Fault
Small earthquakes are common along the New Madrid Fault. This map shows earthquakes from 1974 to 2002 (red circles) and those that occurred prior to 1974 (green circles). Seismologists estimate that there is a 7 to 10 percent probability of a 7.5 magnitude or greater earthquake.