The crustal structure of southeast Tibet from joint inversion of surface wave dispersion and gravity anomaly data

Southeast (SE) Tibet has become a focal point of scientific interest, with an ongoing debate about the presence of crustal flow channels in the region. We built a high-resolution crustal velocity and density model of SE Tibet from joint inversion of surface wave dispersion and gravity anomaly data. We used a 3D joint inversion method to invert for the crustal S-wave velocity and density structure. The joint inversion enhances both model resolution and robustness in comparison to traditional travel-time inversion of surface waves. A notable high velocity anomaly is evident in the crust of the Panzhihua area, potentially indicating an association with the Emeishan Large Igneous Province. We found obviously low velocity and low density anomalies in the middle-lower crust, suggesting that the crust of SE Tibet is ductile and may promote crustal flow. Additionally, there is an obvious low velocity and low density anomaly beneath the Tengchong volcano, suggesting the possible presence of a magma chamber beneath this region. This low-V anomaly beneath Tengchong volcano may be connected to the crustal low velocity channel in SE Tibet.