Estimation of asthenospheric deformation law for the post glacial rebound based on the deformation mechanism map of olivine

Abstract

Linear deformation laws have been applied to post glacial rebound, while many speculations based on real rock samples support non-linear rheology in the upper mantle. Essential information is required to support the assumed constitutive relation. Based on a comparison between present plate motion and formation of seismic anisotropy in the asthenosphere, the critical strain rate between linear and nonlinear deformation laws has a value of about 1~10×10^s^. This critical strain rate for formation of anisotropy due to plate motion has a larger value than typical strain rate of post glacial rebound (1~10×10^s^). Thus, the effective deformation mechanism in the asthenosphere for the post glacial rebound is linear rheology