Technical Basis for Revision of Regulatory Guidance on Design Ground Motions: Development of Hazard- and Risk-consistent Seismic Spectra for Two Sites

We develop recommendations for design spectra at two sites, one in the Mojave desert, California, and the second at Columbia, South Carolina. These sites were chosen because local, small earthquakes dominate the high frequencies (f⩾10 Hz), but large distant events dominate the low frequencies (f⩽1 Hz). Both rock and soil conditions are examined at each site.