By: Marilia A. Ramos, Mihai Diaconeasa, Saeed Nozhati, Arjun Earthperson, and Ali Mosleh

Report prepared for the Nuclear Regulation Authority, Tokyo, Japan.

By: Chukwuebuka C. Nweke, Jonathan P. Stewart, Scott J. Brandenberg

DOI: 10.34948/N3159F

Seismic site response can be influenced by a variety of physical mechanisms that include amplification due to resonance, nonlinearity, topographic effects, impedance contrasts, and contributions from two- or three-dimensional wave propagation in sedimentary basins. Current ground motion models use ergodic procedures that average these effects over many sites globally by conditioning on the time-averaged shear wave velocity in the upper 30 m (VS30), and in some cases, on the depth to a shear wave velocity isosurface (zx) that is also known as the basin depth parameter.