Interesting
THE NEW MADRID FAULT SYSTEM EXTENDS 120 MILES SOUTHWARD from the area of Charleston, Missouri, and Cairo, Illinois, through New Madrid and Caruthersville, following Interstate 55 to Blytheville and on down to Marked Tree, Arkansas. It crosses five state lines and cuts across the Mississippi River in three places and the Ohio River in two places.
THE FAULT IS ACTIVE, AVERAGING MORE THAN 200 MEASURED EVENTS per YEAR (1.0 or more on the Richter scale), about 20 per month. Tremors large enough to be felt (2.5 - 3.0 on the Richter scale) are noted annually. Every 18 months the fault releases a shock of 4.0 or more, capable of local minor damage. The most recent registering 4.3 along the New Madrid Fault on Thanksgiving evening, 1996, which was felt by citizens in the states of Missouri, Arkansas, Tennessee and Kentucky, Illinois and Mississippi. Magnitudes of 5.0 or greater occurring about once per decade, can do significant damage, and be felt in several states.
