弹性介质各向异性研究沿革、现状与问题

THE STUDY OF ANISOTROPY IN ELASTIC MEDIUM:EVOLUTION, PRESENT SITUATION AND QUESTIONS

各向异性介质中地震波的传播研究是当今地震学研究领域中的前沿课题之一,同时也是地震学中难题之一.由于地下岩石的各向异性主要表现在:地震波速度随传播方向发生变化;不同类型体波间相互耦合;横渡发生分裂:面波速度频散依赖于传播方向等.薄互层与裂隙定向分布等产生视各向异性,放在石油地震勘探、地震预测和岩石层物理与动力学研究中有极大潜力和应用前景,并受到广泛重视.为此,本文较为详尽地讨论了弹性介质中地震波各向异性研究的沿革,简述了国内外现今取得的主要研究成果以及目前尚存在的和有待解决的一些主要问题.最后对我国在各向异性介质中地震波动、检测和应用等研究提出了一些看法.

The study of seismic waves propagation in anisotropic medium is one of frontier problems in seismology. It is also one of the difficulty problems. As the anisotropy of the underground rocks mainly manifests that: seismic waves velocities vary with propagating direction, different type body waves couple each other, the dispersions of surface waves Velocities depend on propagating direction, shear waves split, etc., furthermore, thin-layered medium and preferred cracked distribution are induced to apparent anisotropy. So it has great potentiality and bright future in significal applications for oil and gas seismic exploration, earthquake prediction and the study of lithosphere physics and dynamics, and lots of attention were focused on. For that, we discuss the evolution of the study on the seismic waves in elastic anisotropic medium in detail, and review the main achivements obtained home and abroad up to date, propose some main problems which appear in the study and are expected to be solved. In the last, we make some suggestion about the study of seismic wave motion, detection and it's application in anisotropic medium.