资源环境科技发展态势分析平台

We present high-resolution 3D images of the crustal S-wave velocity structure beneath northeastern Tibet, via ambient noise imaging techniques. The data come from continuous recordings taken in one year by a seismic array consisting of 366 broadband stations in the study region. The results show a substantial and pervasive middle crust low-velocity structure (<3.4 km/s) beneath the plateau region, which partially protrudes northeastward across the West Qinling fault, reflecting channel flow from inside the plateau and material extrusion in the periphery. The growth of the northeastern Tibetan Plateau in the study region is manifested in its northeastward expansion and thickening driven by crustal channel flow, accompanied with upper crust shortening.