天然地震数值模拟与实例对比

为了解决长时间正演模拟的不稳定性问题, 实现天然地震波场长时间数值模拟.在高阶有限差分数值模拟的基础上, 给出了多轴向完全匹配吸收边界(M-PML)二维划分方式, 讨论了M-PML吸收边界转换系数P的取值对其吸收能力与截断误差对数值模拟有效信号的影响.实现了二维弹性波高阶有限差分的长时间数值模拟.采用2013年12月16日湖北省巴东县地震及余震信息, 对该地震数据进行了数值模拟, 并与武汉、秭归两台站数据进行了分析和讨论, 验证该正演模拟方法的正确性和有效性.为天然地震波场传播规律、成像和震相识别及震源定位等研究提供了基础. 

Comparison of Natural Seismic Numerical Simulation and Practical Example

In order to resolve the long-time forward modeling instability and realize the long-time numerical simulation of natural seismic wave field, based on staggered-grid high-order difference method, the 2-D model partitioning way of M-PML is provided, the value of the M-PML absorbing boundary conversion coefficient P and its influence on the absorption capacity and the influence on effective signal made by truncation error are discussed, the 2D elastic wave long time numerical simulation using higher-order finite difference is realized. In addition, combining the data of the 5.5 magnitude earthquake which occurred in Hubei Badong on December 16, 2013 and its aftershock recorded by Wuhan and Zigui Seismograph Stations, the practical significance of the forward modeling method is verified. The results can provide a basis for the research of the propagation law, imaging, phase identification and hypocentral location of natural seismic wave field.