On Tuesday over 2 million people participated in the Great Central ShakeOut as an earthquake preparedness drill, a drill that makes one turn back the history books some 200 years.
Two hundred years ago today, the central Mississippi River Valley was violently shaken by the first of a series of three earthquakes of magnitude 7 ?? 8 and hundreds of aftershocks greater than magnitude 3. By March 15, 1812, an estimated 2,000 aftershocks had been felt, but it is likely there were tens of thousands more that were not felt or otherwise noted.
The third and probably the most widely felt of the three major earthquakes occurred on February 7, 1812, at about 3 a.m. There were several destructive shocks that day, the last and largest estimated at magnitude 7.7. As a result, the town of New Madrid, Missouri, was severely damaged.
Now, fast forward 200 years to February 7, 2012, when just after midnight a 2.5 magnitude earthquake reminds the Midwest of why we still do earthquake drills. Tuesday's quake was just 31 miles from Poplar Bluff, MO with a shallow depth of just .1 mile.
Melanie Gade and Heidi Koontz with U.S. Geological Survey contributed to this story. Click here for more from USGS.