Active crustal deformation in southeastern Tibetan Plateau: The kinematics and dynamics

Abstract

Abstract Crustal deformation in southeastern Tibetan Plateau has been attributed to tectonic extrusion and gravitational spreading. Here we analyzed the present-day strain partitioning in this region using GPS data. The results show highly localized shear strain along the Xianshuihe-Anninghe-Xiaojiang strike-slip faults, as expected by the model of tectonic extrusion. However, the localized shear strain along strike-slip faults ends in southern Yunnan and transfers to crustal extension in Yunnan and contraction in Myanmar. We developed three-dimensional visco-elastoplastic finite element models to investigate the causes of the observed crustal deformation. Our results indicate that the present-day crustal deformation in southeastern Tibetan Plateau can be largely explained by gravitational spreading.