Finite Difference Numerical Simulation of Trapped Waves in the Kunlun Fault Zone

Abstract

AbstractIn this paper, we simulated the trapped waves generated by explosions in the Kunlun fault zone, using the three‐dimensional staggered‐grid finite difference algorithm. In order to improve the reliability of final fault‐zone model, we use the data of three components. The simulations indicate that the region above the depth of 1.0 km in the Kunlun fault zone produces main effects on the characteristics of the trapped waves. The S‐wave velocities and the width of fault zone have more effects on arrival times, waveforms, amplitudes and phases of the trapped waves. By simulation, the detailed structure parameters of the Kunlun fault zone are as follows: the width of shallow fault zone is 300m, and 250m in deep; The S‐wave velocity inside the fault zone is 0.98 km/s in the layers above the depth of 400 m, and that of surrounding rock is 1.70 km/s, and the Q value is 13.8. The S‐wave velocities and Q increase with depth. Beneath the depth of 1000 m, the S‐wave velocity inside the fault zone is 2.80 km/s and that of surrounding rocks is 3.3 km/s.