An alternative method for estimating effective elastic thickness by the Vening Meinesz regional isostatic theory with application to continents

Abstract

SUMMARYEffective elastic thickness, ${T_\mathrm{ e}}$, is a measure of the lithosphere's mechanical strength, and describes the flexural response of the lithosphere to applied loads in the same way as a thin elastic plate. In this study, a new method for estimating ${T_\mathrm{ e}}$ in the spatial domain is presented based on the Veining Meinesz regional isostatic theory. By comparing the absolute values of the correlation coefficients between the observed Moho flexure model and different Veining Meinesz Moho flexure models, the optimal ${T_\mathrm{ e}}$ is determined. Also, the estimated correlation coefficients can be used to examine the effect of the unknown subsurface loads, which are usually difficult to evaluate in the spatial domain. This method is verified to be capable of recovering ${T_\mathrm{ e}}$ variations through synthetic tests for the models with predefined ${T_\mathrm{ e}}$ variations. Finally, the effective elastic thickness is globally determined for the continents using the topography data and recent seismically-derived Moho model. These results are compared with two published ${T_\mathrm{ e}}$ models obtained with different methods. For the areas with relatively small Moho uncertainties and high correlation coefficients, the estimated ${T_\mathrm{ e}}$ variations generally agree with previous results. The differences between three ${T_\mathrm{ e}}$ estimates could characterize the advantages of different methods in specific cases.