Recent advances in deep mantle rheology

Abstract

In this article, the following recent advances in the deep mantle rheology are reviewed. (1) High-precision global gravity data put new constraints on the present deformation of the deep mantle and, in turn, mantle viscosity. (2) Anisotropic structure has been revealed in the mantle transition zone and the lower mantle. (3) Pressure condition of strain-rate controlled deformation experiments has been expanded to 15-25 GPa at 1700-2100 K. New insight into dynamics of the Earth's interior should be brought by interpreting the new geophysical observations with rheological data that will be obtained by the advanced deformation experiments.