Near-Source Attenuation Relationship for the Geometric Mean Horizontal Component of Peak Ground Acceleration and Acceleration Response Spectra

Empirical ground motion models for the average horizontal component of peak groundmotion and acceleration response spectra from shallow crustal earthquakes are derived using near-source database. These models were derived using a worldwide dataset consisted of corrected and processed accelerograms of 646 strong-motion records recorded with 60 (km) of the surface projection of earthquakes between Mw 5.2 and 7.8. Model is function of earthquake mechanism, distance from source to site, local average shear wave velocity, nonlinear soil response, sediment depth, depth-to-top of rupture, hanging wall effects and faulting mechanism. Non-linear site effects are constrained by equivalent linear models. An important additional source parameter, depth to the top is also included. The hanging wall effect is included with an improved model that varies smoothly as a function of the source properties, such as magnitude, dip, distance, depth, and the site location.