A coupled thermal-fluid-solid approach for modeling the lithosphere-asthenosphere interactions

Lithosphere-asthenosphere interaction is now one of the hot issues in geodynamics. In order to model the interaction between lithospheric deformation and asthenosphere convection, a coupled thermal-fluid-solid approach is proposed and the corresponding finite element codes are developed. This new method avoids the deficiencies of pure mantle convection or pure solid mechanical systems. This approach describes the lithosphere-asthenosphere interactions, including the mantle movement driven by thermal heterogeneity (and/or dragged by the moving plate), the deformation of lithosphere caused by exerting force induced by the convective mantle on coupled boundary, the responses of mantle convection in shape to the deformed lithosphere. The multiple interrelated processes promote the evolution of lithosphere-asthenophere system. This approach is used to simulate topography uplift under a mantle plume and the results are consistent to geological reality and conventional cognition, certifying its validity and capability to deal with complex coupled issues.