Abstract:Using 190 broadband temporary stations in the Sichuan-Yunnan region from 2011 to 2013, we analyze Rayleigh surface wave phase velocity and anisotropic structure from 6 s to 60 s of the crust and upper mantle in Sichuan-Yunnan region based on eikonal equation tomography and Helmholtz equation tomography. The results show that: 1) The anisotropy direction of the upper crust is consistent with the trend of the surface structures, reflecting the tectonic movement characteristics of the southeast extrusion of the Sichuan-Yunnan block. 2) There are low velocity anomalies with strong anisotropy in the middle and lower crust of Sichuan-Yunnan block, which is consistent with the middle and lower crust flow model. 3) Bounded by 26°N, the anisotropy direction is different between crust and upper mantle in southern Sichuan-Yunnan, indicating that crust-mantle deformation is decoupled in this region. 4) The long period surface wave anisotropy direction is nearly EW direction, which is consistent with the shear wave splitting. It may be caused by the east-subduction and retracement of the Indian plate.