Application of shallow shear-wave seismic reflection methods in earthquake hazards studies

Abstract

In engineering geophysics, the use of shear-wave seismic methods for earthquake hazards analysis has primarily been limited to site-specific downhole, crosshole, and refraction studies for velocities to model site response to earthquake shaking and/or liquefaction potential. This paper demonstrates the utility of S-wave reflection methods in earthquake hazards studies, focusing on areas where collection of high-quality compressional-wave reflection data is problematic. Specific examples will show how S-wave reflection data help interpret the age, style, and extent of near-surface deformation in the New Madrid seismic zone of the central United States, and in mapping the Holocene-Pleistocene surface beneath the Fraser River delta in southwestern British Columbia (Canada).