February 7, 2015 is the 203rd anniversary of the last of these great quakes, which forever changed the mid-western landscape; and were felt across the U.S. and as far south as the Gulf of Mexico, and as far north as Canada.
While scientists say that there is only a 7-10% probability of a re-occurrence of these earthquakes within any 50-year window, they also estimate that there is a 25-40% probability of a M6.0 or greater earthquake occurring in the central U.S. within the same period of time. About 200 earthquakes occur in the central U.S. every year-many of which go unnoticed.
While the primary focus remains on the NMSZ, it is not our only area of concern. Earthquakes are also occurring along the Wabash Valley and East Tennessee Seismic Zones and in Oklahoma, Kansas, Ohio, and Texas.