Ground‐Motion Prediction Equation for the Chilean Subduction Zone

Abstract

Abstract A ground‐motion prediction equation for the horizontal component of the response spectral values from the Chilean subduction zone is developed. The dataset contains 3774 recordings from 473 earthquakes, including the latest megathrust events that occurred in the country (i.e., 2010 M w  8.8 Maule, 2014 M w  8.1 Iquique, and 2015 M w  8.3 Illapel). The functional form for the median model follows the proposal by Abrahamson et al. (2016). Site effects are estimated based on V S 30 . An additional model is built using only ground motions associated with measured values of V S 30 and reliable M w estimates (termed the high‐quality [HQ] model). The standard deviation of the HQ model is much lower than the main model, particularly the component of the standard deviation that corresponds to site‐to‐site variability, indicating that better site characterization can significantly reduce the overall uncertainty in ground‐motion estimation. Electronic Supplement: Tables of regression coefficients for the high‐quality (HQ) model and 95% confidence intervals for model’s coefficients and MATLAB implementation of the ground‐motion prediction equation (GMPE).