Sources of the present-day tectonic stresses in Central Europe: inferences from finite element modelling

Adigital two – dimensional elastic model was built to investigate the recent tectonic forces and stresses in Central Europe. Stresses and deformations were calculated using finite element method. The structure of model includes geologically defined features: 32 tectonic blocks, 16 fault zones and 12 boundary segments. The loads were implemented in two ways: as the external boundary forces and the correction due to differences in gravitational potential energy. The calculated stress directions and regimes were satisfactorily matched to the complex stress pattern in Central Europe provided by the World Stress Map Database. Modelling permits evaluation of tectonic forces acting in the collision zone between Africa and Arabia on one side, and Europe on the other side. Also the Mid-Atlantic Ridge push differentiation on the NWEuropean passive margin was determined. For the centre of modeled area the magnitudes of tectonic stresses averaged over the changeable lithospheric thickness were computed. Obtained values of friction coefficients for the fault zones located in the southern part of Europe are significantly lower than those obtained for the northern Europe. The maximum acceptable stiffness contrast across the model reaches one order of magnitude