关键词: 活断层, 浅层地震勘探, 沿海地区, 隐伏断层

Abstract: The depth of Quaternary in China coastal zone varies greatly.In most areas,silt,clay and sand are always multiply interbedded.This kind of formation can attenuate greatly the high frequency signal,and is unfavorable to propagation of seismic wave.At the same time,the density of population in the area is much higher and the industrial noise is strong,so the trigger and receiver conditions are not ideal.The paper presents some application examples of detecting buried faults with near-surface seismic methods in east Guangdong,Tianjin and Tangshan where the thickness of overburden varies greatly,and systemically introduces the methods of fieldworks,data processing and explanation approaches.It also illustrates the effective methods of how to improve SNR and resolution in environment with strong noise.In the application,the signal of refection is strong and the buried faults can be reflected evidently.Proofs of drilling at both sides of the faults approve that the depth of interface,location of fault point and throw of basement determined by seismic exploration are all reliable.The techniques and methods mentioned in this paper are of important reference value in urban active fault detection and engineering geophysical prospecting in similar areas.

Key words: active fault, shallow seismic exploration, coastal area, buried fault