Ground motion prediction equation for Taiwan subduction zone earthquakes

Abstract

A ground motion prediction equation (GMPE) is presented for computing the median and standard deviation of peak ground acceleration (PGA) and 5% damped pseudo-spectral acceleration (PSA) for periods between 0.01 s and 5.0 s for probabilistic seismic hazard analysis (PSHA) and engineering applications in Taiwan. An integrated strong motion dataset consisting of two subduction earthquake regions was selected from 3314 recordings from Taiwan with M4.5 to M7.1 and 3376 recordings from Japan with M6.5 to M9.1. This dataset was then used to validate, and refit where necessary, the function form provided by Abrahamson et al. for application to Taiwan subduction earthquakes. The proposed model accounts for the extrapolation behaviors associated with the large-magnitude scaling and the near-source scaling terms, both of which were developed empirically by using the combined Taiwan–Japan dataset. The distance attenuation and site term were developed specifically for the Taiwan region. The site term is based on two parameters; the time-averaged shear wave velocity of the top 30 m depth ( VS30) and the depth-to-the-shear wave velocity horizon of 1.0 km/s ( Z1.0).