Kentucky Research Consortium for Energy and Environment (KRCEE): New Madrid Scope

Woolery and Almayahi (2014) recently collected a series of high-resolution seismic-reflection profiles at the Central United States Seismic Observatory (CUSSO) site that imaged a set of steeply dipping N 30° E striking faults with uplifted and arched post-Paleozoic sediments in a manner consistent of dextral transpressional displacement. The adjacent well-constrained CUSSO borehole log allowed them to establish the sub-parallel fault strands Quaternary-active. In addition, their projecting these faults along the northeast strike 22 km to an intersection with the nearest subsurface dataset (i.e. lower-resolution industry seismic reflection profile) immediately south of Wolf Island, Missouri, coincided with a discrete 0.75-km-wide set of observable faults having the style and offset similar to those imaged by the high-resolution lines. Now, for Field Investigation #1 we seek to acquire a series (~5 km) of high-resolution P- and SH-wave seismic reflection profiles at the 12-km back-strike-projection intersection with a right-lateral offset in the Reelfoot scarp stepover. Positive confirmation for the southwest fault zone extension, along with the previously defined northeast extension, will provide kinematic and geographic evidence for a hypothesized northeast continuation of the NMSZ’s southern Axial shear zone across the central stepover, thus accommodating the problematic differential right-lateral strain observed between the surface scarp and seismogenic depth (Odum et al., 2010; Pratt et al., 2012). Confirming the first physical evidence toward the long-standing strain accommodation problem will provide a conceptual leap in our understanding of the seismotectonic kinematics for the NMSZ in general, and a reduction in the seismic hazards uncertainty in particular.