Geologic implications of earthquake source parameters in central and eastern North America

Well-constrained depths and dips for 20 shocks in central and eastern North America (CENA) with magnitudes between 4.9 and 6.8 were compiled. The appendix lists the values chosen, reasons for selecting specific values, and the uncertainties associated with each value. The median depth is 10km, but an aseismic interval from about 15 to 25km depth separates three midcrustal hypocenters from the others. These results combined with geologic evidence suggest various inferences about earthquakes with M???4.9 in CENA. -from Authors