Evaluation of Ground Motion Prediction Equations (GMPEs) for Chile Subduction Zone

In this study we present an evaluation of the performance of the latest ground motion prediction equations for Chilean subduction zone. Ground-motion prediction equations (GMPEs) for earthquakes that occur in subduction zones are a key input to seismic hazard analyses and risk mitigation. In this study, we use recent large subduction events recorded in Chile, including Valparaiso (Mw 7.9), Maule (Mw 8.8), Iquique (Mw 8.1) and Southern Peru (Mw 8.4). We use shear-wave velocity profiles that were obtained for several stations through surface wave dispersion methods using active and passive sources, this represents a significant contribution to earthquake hazard mitigation in Chile, as this information is useful for a number of projects that tribute towards that end. All records were processed following state of the art procedures to obtain comparable signal to noise level and detrended records, the processing was performed component by component. Response spectra of the recorded ground motions were compared with those predicted by BCHydro [1], Ruiz & Saragoni [2], Atkinson & Boore [3][3], Boroscheck & Contreras [5] and, Zhao et al. [6] ground motion prediction models. Results show that at low frequencies BCHydro has the best predictive capacity, while Zhao et al. is the best performing GMPE for high frequencies. Most of the tested GMPEs underestimate spectral accelerations.