Wabash Valley Seismic Zone is where this one came from (I could not remember the name of it earlier)
Wabash Valley Seismic Zone
Recent studies have indicated that the New Madrid Seismic Zone is not the only ‘hot spot’ for earthquakes in the Central United States. On June 18, 2002, a 5.0 magnitude earthquake struck the Evansville, Indiana with an epicenter between Mt. Vernon and West Franklin in Posey County, in an area that is part of the Wabash Valley Seismic Zone. According to the Indiana University Indiana Geological Survey, while there was minor damage associated with the earthquake, the tremor was a warning to residents of the Wabash Valley Seismic Zone that earthquakes can, and do, strike close to home.
The Wabash Valley Seismic Zone is located in Southeastern Illinois and Southwestern Indiana and it is capable of producing ‘New Madrid’ size earthquake events. Since the discovery of this seismic zone, earthquake awareness and preparedness have increased. Residents are seeing that moderate sized earthquakes are not just occuring to south, but occur right at home and can affect Illinois, Indiana, and Kentucky.
Geologists in Indiana and Illinois have found liquefaction sites and sand dikes that shows the evidence of prehistoric earthquakes in the region. By examining the size of the dikes and sediment found within the sand dikes, geologists are able to estimate the size of the earthquake it took to create the formations. In the mid-1980’s, geologist Steven Obermeier found a liquefaction formation that was estimated, through carbon dating, to be 6,100 years old. The earthquake that produced the site was estimated to be a magnitude 7.0, large enough to seriously disrupt the area known as the Wabash Valley Seismic Zone.
Current research is still turning out new evidence of historic earthquakes in the zone.