Geologic Cracks Record

Schematic locations, spatial densities, map distribution, and orientations of coseismic sackungen based on the New Madrid seismic zone. Reverse faulting produces ridgetop sackungen with higher densities and at greater distances from the fault trace in the hanging wall than in the footwall. Strike-slip faulting produces ridgetop sackungen having equal densities and distances on both sides of the fault, with a smaller overall distance from the fault trace than a reverse fault. Strong fault-normal shaking and/or static shear strain produces fault-parallel sackungen with fault-normal spreading for reverse and strike-slip faults. Grey shading darkens with increased deformation/static shear strain.