黏弹性EDA介质中地震波的传播特征  

Propagation characteristics of seismic wave in EDA viscoelastic medium

作　　者：何现启[1] 朱自强[2] 彭凌星[1] 鲁光银[2] 

机构地区：[1]湖南省交通规划勘察设计院,长沙410008 [2]中南大学地球科学与信息物理工程学院,长沙410083

出　　处：《地球物理学进展》2017年第1期363-370,共8页Progress in Geophysics

基　　金：国家自然科学基金项目(41174061)资助

摘　　要：地球介质基本为黏弹性各向异性介质,研究黏弹性各向异性介质中地震波的传播特征对提高地震勘探精度及准确性有着重要意义.相速度与群速度是认识黏弹性各向异性地震波传播规律的主要参数,对地震数据解释具有重要意义.本文基于特殊分量法,通过求解christoffel方程,推导出黏弹性EDA介质中均匀、非均匀波的精确相速度、慢度和群速度公式,并通过模型计算研究了SH波的相速度特征及其随相角和不均匀参数D的变化规律.结果表明D影响了地震波的相速度大小,但对其方位特性无影响,在EDA介质中相速度随方位角变化的规律仍然可指示介质的对称轴方向和裂隙的走向.Nearly all the media of earth is viscoelastic anisotropic,study of the characteristics of seismic wave in viscoelastic anisotropic media is of great significance to improve the precision and accuracy of seismic exploration. Phase velocity and the group velocity is the main parameter to recognize propagation characteristics of seismic waves in viscoelastic anisotropic media and have important significance to seismic data interpretation. Based on the special component method,accurate phase velocity,slowness and group velocity formula of inhomogeneous wave and homogeneous wave in EDA viscoelastic medium is derived by solving the equation christoffel. The characteristics of phase velocity of SH wave variation with phase angle and inhomogeneous parameter D is studied by numerical calculation. The results show that inhomogeneous parameter affects the magnitude of phase velocity,but no effect on the orientation characteristics. In EDA media,characteristics of phase velocity variation with azimuth can still indicate the direction of the axis of symmetry and cracks.

关 键 词：黏弹性 EDA 地震波 相速度 群速度 

分 类 号：P631[天文地球—地质矿产勘探]