Pseudo-dynamic earthquake source modeling, current status and prospect

Physics-based ground motion prediction studies are an essential element for advanced seismic hazard assessment. They make it possible to understand and predict the characteristics of near-source strong ground motions from future scenario earthquake models, which makes its importance greater in regions where observational data are scarce. Empirical Ground Motion Prediction Equations (GMPEs) or stochastic strong ground-motion simulation methods have been mainly used in the community, but recently, strong ground-motion simulation approaches with fault-based earthquake source are becoming more attractive. They consider both the mechanical rupture process of an earthquake fault and the seismic wave propagation by adopting either dynamic or pseudo dynamic earthquake source modeling. In this review, we stated the research trends and prospects of the pseudo dynamic source modeling, which are expected to be more usable because of their computational efficiency. Although there are still challenges to be overcome, such as improving the input values of pseudo-dynamic source models, upgrading the complexity of the probabilistic model, and extending to high-frequency band (> 1 Hz), this method may overcome the limitations of the empirical GMPEs or stochastic simulation methods. We expect that it will greatly contribute to conducting advanced seismic hazard assessment and mitigation studies in the Korean Peninsula where observational strong ground-motion data are absolutely lacking.