Evaluation of stress and strain rates in the lithosphere of Europe based on high resolution thermodynamic model coupled with mantle convection model.

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The total stress field within the lithosphere represents a sum of the stresses originated at plate boundaries, global mantle flow at the bottom and local stresses largely related to the heterogeneous lithosphere structure. Existing numerical stress models for Europe have been developed taking into account chiefly plate boundary forces, which magnitude is not well determined, and considering oversimplified rheology models and lithospheric structure. However, other factors, e.g. influence of the vertical and horizontal forces caused by mantle convection and post-glacial relaxation, as well as strong lateral heterogeneity of the lithosphere and topography are not well considered in the models. The main goal of the study is calculation of the lithospheric stress field of Europe taking into account all the major factors. This shall be done by means of 3D high-resolution thermo-mechanical and density model of the lithosphere coupled with the global mantle convection model. Based on recent structural and rheological models and using the finite-volume approach (code LAPEX 3D, which operates with temperature- and stress-dependent visco-elasto-plastic rheology) we are going to develop a spatial multi-scale (nested mesh) technique to avoid uncertainties in boundary conditions and refine domains with high-gradient physical fields (strain rate, stress). Reliability of the final model will be evaluated by comparison with GPS data, experimental stress determinations and other available data.