天然地震数值模拟与实例对比

Comparison of Natural Seismic Numerical Simulation and Practical Example

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.

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 provid-ed,the value of the M-PML absorbing boundary conversion coefficient P and its influence on the absorption capacity and the in-fluence 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 1 6,2013 and its aftershock recorded by Wuhan and Zigui Seismograph Stations,the practical sig-nificance 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.