A new approach for associating earthquakes with geological structures : Application to epicenters in southern Illinois and southeastern Missouri

Abstract : A spatial statistical analysis method has been applied successfully on diffuse seismicity of southern Illinois and southeastern Missouri. The study area is a region of diffuse deformation and seismicity close to the New Madrid Seismic Zone. The New Madrid Earthquake Catalog is examined through the Blade Method applied on collapsed epicenters. This is a new approach since the Blade Method is applied on improved locations through the Best Estimate Method. The Blade Method performs tests on binomial distributions for the detection of significant seismic alignments within a sparse epicenter distribution. From the epicenters of the New Madrid Earthquake Catalog, using the Blade Method on collapsed epicenters, it is statistically valid to state that seismicity is associated with the New Madrid Seismic Zone and the Black, Ellington, Salem and Ste Genevieve faults.