断层带围陷波研究及其应用进展

The research and application progress in fault zone trapped waves

断层带结构研究对于认识地震的孕育发生、地震破裂过程及其地震灾害具有重要的意义,因而多种方法被用来观测和研究断层带结构,其中断层带围陷波就是有效方法之一.断层带围陷波是由地震波入射到断层带内低速介质与高速围岩之间的界面时在界面内侧经多次反射相干叠加形成,具有大振幅、低频率和频散的特点.由于断层带围陷波在断层带的内部传播,它携带有断层带的介质物性和结构的重要信息,因此可以利用围陷波的波形特征研究断层带的精细结构.本文详细介绍了断层带围陷波的形成机制、传播和特性,全面阐述了断层带围陷波在观测研究、传播和特性理论研究和利用围陷波反演断层带结构的方法及应用三个方面的进展,并探讨了断层带围陷波研究方面存在的不足和问题.

The study of fault-zone structures has important significance for understanding earthquake preparation and occurrence, the course of rupture and earthquake disasters. There are many methods of exploring and studying fault zone structures, and the application of fault zone trapped waves is one effective way. When seismic waves radiated from the inner incidence to the interface between the low-velocity media and high-velocity surrounding rock, coherent multiple reflections are formed inside the fault zone. By wave interference and stack, fault zone trapped waves are formed. And the wave- trains have the characteristics of large amplitude, low frequency and dispersion. Fault zone trapped waves contain much important information of fault zones because they propagate along the inner of fault zones. The information can be used to study the fine structures of fault zones. In this paper, we introduce in detail the formation mechanism, propagation and characteristics of fault zone trapped waves. And this paper gives an overall explanation of research progress on trapped waves from three aspects： observations of trapped waves, propagation and characteristics theoretical study, and inversion methods and application of fault zone structures on trapped waves. Finally, this paper discusses the shortcomings and problems on the research of trapped waves .