Evaluation of Biases in Ground Motion Prediction Equations for Subduction Earthquakes in Taiwan

Taiwan is located at the boundary of Philippine Sea plate and Eurasian plate. These two plates converge at a rate of 8 centimeters per year (Yu et al., 1997). To the south of Taiwan, Eurasian plate is subducting below the Philippine Sea plate; while to the, northeast, the Philippine Sea plate is subducting below the Eurasian plate. Collision of these two plates leads to significant compression and friction accumulated in the region along the boundary. On average, there are more than 2000 earthquakes annually in Taiwan. The focal depths of these earthquakes can be shallow or occurring at a depth of several hundreds of kilometers. Ground motion prediction equations (GMPEs), which are empirical models derived from past earthquake recordings, are often used to estimate ground motion intensity level at a site for an earthquake of particular magnitude. GMPEs consist of parameters that would describe the source, path and site effects. In this study, the GMPE models developed by Lin and Lee (2008) and Abrahamson et al. (2016) are reviewed. By using the subduction earthquakes from Taiwan, applicability and biases associated with these models are evaluated.