In this study, we conducted ambient noise tomography(ANT), with 33-day data, to investigate the nearsurface shear-velocity structure in downtown Ji’nan, Shandong Province, China. The cross-correlation functions with ...In this study, we conducted ambient noise tomography(ANT), with 33-day data, to investigate the nearsurface shear-velocity structure in downtown Ji’nan, Shandong Province, China. The cross-correlation functions with quiet clear Rayleigh waves are obtained with more symmetrical energy distribution which indicates that strong human activities, such as moving vehicles and municipal engineering construction, can produce approximately isotropic distribution of noise sources for high-frequency signals. The direct surfacewave tomographic method with period-dependent ray-tracing is used to invert all surface-wave dispersion data in the period band 0.2–1.5 s simultaneously for 3D variations of shear-velocity structure. The study result can help us better understand the local geologic structures, evaluate the distribution and geometry of the fracture-karst media, and assess hazards of the concealed active fault and its effect on the springs in the future.展开更多
基金supported by China Geological Survey's project(Nos.and DD20189132)Basic Scientific Research project from Chinese Academy of Geological Sciences(No.YWF201901-02)The National Key Research and Development Program of China(Nos.2016YFC0600201,2016YFC0600208 and 2016YFC0600209)
文摘In this study, we conducted ambient noise tomography(ANT), with 33-day data, to investigate the nearsurface shear-velocity structure in downtown Ji’nan, Shandong Province, China. The cross-correlation functions with quiet clear Rayleigh waves are obtained with more symmetrical energy distribution which indicates that strong human activities, such as moving vehicles and municipal engineering construction, can produce approximately isotropic distribution of noise sources for high-frequency signals. The direct surfacewave tomographic method with period-dependent ray-tracing is used to invert all surface-wave dispersion data in the period band 0.2–1.5 s simultaneously for 3D variations of shear-velocity structure. The study result can help us better understand the local geologic structures, evaluate the distribution and geometry of the fracture-karst media, and assess hazards of the concealed active fault and its effect on the springs in the future.
