Arash Zandieh of LCI has authored a technical paper entitled, “Estimation of κ0 Implied by the High-Frequency Shape of the NGA-West2 Ground-Motion Prediction Equations”. Arash’s co-authors are Ken Campbell and Shahram Pezeshk at CoreLogic, Inc. and The University of Memphis, respectively.
Authors used the inverse random vibration theory approach to calculate Fourier amplitude spectra from predicted values of response-spectral acceleration for all five Next Generation Attenuation (NGA)-West2 ground-motion prediction equations (GMPEs). Authors used these spectra to estimate κ0 using the spectral-decay method. Each GMPE was evaluated for a National Earthquake Hazard Reduction Program B/C site condition and for default estimates of depth to the top of rupture, hypocentral depth, and sediment (basin) depth. Authors derived estimates of κ0 for magnitudes ranging from 3.5 to 8.0 and distances ranging from 5 to 20 km and used a mixed-effects model to derive equations for these estimates as a function of magnitude. The values of κ0 obtained in this study are intended to represent the high-frequency shape of the median predicted spectral accelerations from the GMPEs. The κ0 model developed in this study can be used in inversions to develop stochastic models that are intended to mimic the predictions from the NGA-West2 GMPEs. A copy of publication is available at BSSA website.