Mechanical problems in geodynamics and work done in China

The subject of geodynamics concerns the dynamics of the global motion of the earth, of the motion in the earth's interior and its interaction with surface features, together with mechanical processes in the deformation and rupture of geological structures. A brief historical review is given from Sir I. Newton, Maclauwin, Jacobi, Poincaré, Poisson, Lamé, Darwin, Rayleigh, and Love, who dealt with the homogeneous sphere, to Leibenson, Takeuchi, and Meinesz, concentrating on layered spheres, and after the advent of plate tectonics, on the use of numerical simulation, to the analyses of tectonic features, earthquake mechanism, the application of nonlinear dynamics. By discussing the forward and inverse mechanical problems, and the questions facing the inverse problems of searching for the structural parameters, driving forces, etc. are raised in more detail. Thereafter, some works accomplished in China on the global and regional stress fields analyses; tectonic features' analyses, mantle flow studies; experimental studies of rocks and their constitutive relations are presented. Finally, the interdisciplinary nature of the subject is emphasized, and the main mechanical problems that need special attention are then proposed.