论文部分内容阅读
地震波的旋转运动研究是地球动力学中的一个新兴领域.本文基于弹性波理论推导出旋转速度与相速度的关系,通过Kelvin-Christoffel方程推导了TI介质中地震波相速度的计算公式,从而得到TI介质中的Thomsen参数与旋转速度之间关系;继而借助于几个典型的TI介质模型模拟了地震波旋转运动.模拟结果显示:qP波旋转速度随着ε、δ的增加逐渐增大;qSV波旋转速度随着ε的增大而减小,随δ增大而增大;qSH波旋转速度随γ、δ的增加而增大,且γ的影响更大.另外,从相速度与旋转速度对比发现:qP波和qSH波旋转速度即不是圆形也不是椭圆,相对于相速度更具有方向性,这说明相对于平移运动,旋转运动的信息更有方向性和各向异性.
The study of rotational motion of seismic waves is a new field in geodynamics.In this paper, the relationship between rotational velocity and phase velocity is deduced based on elastic wave theory, and the formula of seismic phase velocity in TI media is deduced by Kelvin-Christoffel equation, Then the relationship between Thomsen parameter and rotation speed in medium was simulated.Then several typical TI media models were used to simulate the rotational movement of seismic wave.The simulation results show that the rotational speed of qP wave increases with the increase of ε and δ, The velocity decreases with the increase of ε and increases with the increase of δ. The rotational velocity of qSH wave increases with the increase of γ, δ, and the influence of γ is greater. In addition, from the comparison of phase velocity and rotation velocity : qP wave and qSH wave rotation speed that is not circular nor elliptical, relative to the phase velocity more directional, indicating that compared to the translational movement, rotational movement of information more directional and anisotropic.