弹性波交错网格高阶有限差分法波场分离数值模拟

 地震波中的弹性波传播会产生纵波和横波，所以用完全弹性波波动方程进行弹性波波场数值模拟时，只能得到纵横波耦合的混合波场。本文从P波波场为无旋场，而S波波场为无散场的思路出发，推出满足此条件的一阶速度—应力弹性波波场分离方程，并利用交错网格高阶有限差分法对波场分离方程进行数值模拟。模拟实例表明，此方法不但成功地将P波波场和S波波场从混合波场中分离出来，而且这种方法的稳定性好、模拟精度高，可用于弹性波传播规律研究及地震资料处理。

Numeric simulation of elastic wavefield separation by staggering grid high-order finite-difference algorithm

Elastic wave propagation of seismic waves can produce P-wave and S-wave,therefore, using full e-lastic wave equation to carry out numeric simulation of elastic wavefield can only get hybrid wavefield coupling P-wave with S-wave. Starting from the idea of P-wave wavefield being rotation-free field and S-wave divergence-free field,the paper deduced separation equation of first-order velocity-stress elastic wavefield, which meets this condition, and used staggering grid high-order finite-difference algorithm to carry out numeric simulation of wavefield separation equation. The simulated cases showed that the approach not only can successfully separate P-wave wavefield from S-wave wavefield in hybrid wavefield, but also is characterized by good stability and higher simulated precision, which can be used for studying the rule of elastic wave propagation and seismic data processing.