The research and application progress in fault zone trapped waves

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 wavetrains 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.