Strong Ground-Motion Simulation Of The 12 May 2008 M-W 7.9 Wenchuan Earthquake, Using Various Slip Models

On 12 May 2008, a devastating earthquake of M-w 7.9 occurred in the Sichuan Province of China. The earthquake had disastrous consequences and cost more than 69,000 lives. The rupture occurred along a 300-km-long fault dipping northwest along the Longmen Shan fold-thrust belt, which separates the Longmen Shan of the Tibetan Plateau in the northwest from the Sichuan Basin in the southeast and is associated with a significant change in the crustal thickness. We simulate the ground shaking due to the Wenchuan earthquake by applying a hybrid broadband frequency strong ground-motion simulation technique that combines deterministic simulation of low frequencies (0.1-1.0 Hz) with semistochastic modeling of high frequencies (1.0-10 Hz). We use three available finite fault-slip models obtained from waveform inversion as input models for the earthquake scenarios. The resulting simulations reveal large variations in ground shaking due to the rupture complexity in terms of a variety of factors, including the location of asperities and the width of the fault plane. The applied methodology successfully reproduces the strong ground-motion distribution and frequency content of the seismic waves. The simulated ground motions, when calibrated with the recorded data, can also be used to verify the finite fault-slip models based on different teleseismic data and inversion schemes. Comparison with the damage distribution from reconnaissance field observations confirms the fault rupture complexity. The applied simulation methodology provides a promising platform for predictive studies.