due to plate boundary processes [Grünthal and Stromeyer (1992)] H direction World Stress Map: 958 data 55.5 % oriented around the NW-SE direction [135°30°] Heidbach et al. (2007; 2010) : in Europe, wavelengths 200 km are frequent

force density integrated on the lithosphere thickness is proportional to the geoid gradient: The local stress, associated to the additional body force density created in a column of lithosphere, is related to the space variations of the two components of F(x,y) T. Camelbeeck, O. de Viron, M. Van Camp and D. Kusters (2013). Local stress sources in Western Europe lithosphere from geoid anomalies, Lithosphere, doi: 10.1130/L238.1 HYPOTHESIS - Geoid as a proxy of the GPE - Isostatic compensation - Slow variations of lithospheric thickness - …

and earthquake fault-plane solutions (2) Comparison of the earthquake mechanism slip direction with the shear stress direction in the fault plane from the geoid. By comparing from the mechanisms of the 9 earthquakes with M greater than 4.5, 7 are explained by the local stress sources whereas 5 are explained by the far field stresses

and at the bottom of the lithosphere are negligible, the vertical stress at depth z in the lithosphere is a principal stress where ρ (z) is the density at depth z and h is the surface elevation The averaged value of the lithostatic pressure in the lithosphere is:

gravitational potential energy of a reference column in which the stress state is assumed to be zero ( in the absence of far-field forces) The solution is: tensile stress compressive stress

per unit length in an isostatically compensated lithosphere due to the lateral differences of density, as well as of surface topography as a function of the surface geoid anomaly : Turcotte and Schubert (2002) For a 100 km thick lithosphere: = 1 m is equivalent to a stress of 2.3 MPa

force density integrated on the lithosphere thickness is proportional to the geoid gradient: T. Camelbeeck, O. de Viron, M. Van Camp and D. Kusters – LITHOSPHERE, doi: 10.1130/L238.1, 2013. HYPOTHESIS - Geoid as a proxy of the GPE - Isostatic compensation - Slow variations of lithospheric thickness - …

associated to the additional body force density created in a column of lithosphere, is related to the space variations of the two components of F(x,y) Principal horizontal stresses from the diagonalisation of the tensor Vertical principal stress from

the geoid and the World Stress Map in Western Europe Misfit between evaluations from the WSM and second partial derivatives of the geoid Our results explain 71% of the earthquake mechanisms for the earthquake fault-plane solutions in the WSM, which is better than the classical compressive NW-SE stress field model.

and earthquake fault-plane solutions (2) Comparison of the earthquake mechanism slip direction with the shear stress direction in the fault plane from the geoid. By comparing from the mechanisms of the 9 earthquakes with M greater than 4.5, 7 are explained by the local stress sources whereas 5 are explained by the far field stresses

via the definition of the Airy stress function , related to the stress components by: The stress function is the solution of the bi-harmonic equation: is the Poisson ratio