Synthetic Ground-Motion Simulation Using a Spatial Stochastic Model with Slip Self-Similarity: Toward Near-Source Ground-Motion Validation

• Main Authors: Ya-Ting Lee, Kuo-Fong Ma, Ming-Che Hsieh, Yin-Tung Yen, Yu-Sheng Sun
• Format: Article
• Language: English
• Published: Chinese Geoscience Union 2016-06-01
• Series: Terrestrial, Atmospheric and Oceanic Sciences
• Subjects: Scenario source model; Slip scaling; Asperity; Ground-motion prediction; Near-fault motion
• Online Access: http://tao.cgu.org.tw/index.php/articles/archive/geophysics/item/download/2161_af4e6c2821da1eed1391add21edc75fa

Near-fault ground motion is a key to understanding the seismic hazard along a fault and is challenged by the ground motion prediction equation approach. This paper presents a developed stochastic-slip-scaling source model, a spatial stochastic model with slipped area scaling toward the ground motion simulation. We considered the near-fault ground motion of the 1999 Chi-Chi earthquake in Taiwan, the most massive near-fault disastrous earthquake, proposed by Ma et al. (2001) as a reference for validation. Three scenario source models including the developed stochastic-slip-scaling source model, mean-slip model and characteristic-asperity model were used for the near-fault ground motion examination. We simulated synthetic ground motion through 3D waveforms and validated these simulations using observed data and the ground-motion prediction equation (GMPE) for Taiwan earthquakes. The mean slip and characteristic asperity scenario source models over-predicted the near-fault ground motion. The stochastic-slip-scaling model proposed in this paper is more accurately approximated to the near-fault motion compared with the GMPE and observations. This is the first study to incorporate slipped-area scaling in a stochastic slip model. The proposed model can generate scenario earthquakes for predicting ground motion.