Africa-Eurasia kinematics control of long wavelength tectonic deformation in the central Mediterranean

We use a spherical thin sheet geophysical model to study the regional deformation pattern in the CentralMediterranean and compare model predictions with the deformation resulting from newITRF2005 data, in terms of both amplitude and direction of the strain rate eigenvectors. We quantify the effects of the choice of a specific data set in defining the boundary conditions for Africa–Eurasia convergence in a predictive model that spreads the information resulting from a discrete data set over a continuum, such as the geodetic one. The fairly good agreement between geodetic and modelled patterns shows that, within the study area, the deformation predicted by tectonic models based on ITRF2005 boundary conditions (b.c.) for Africa–Eurasia relative motion differs from that predicted by models based on Deos2k b.c., only on long distances from the Africa–Eurasia boundary. Geodetically retrieved SSE–NNW compression and SSW– NNE extension are well reproduced by the eigenvectors of the strain-rate tensor in the central Mediterranean and Italian peninsula, with eigenvalues generally slightly underestimating the observed ones, resulting in a global strain-rate of the order of a few nanostrain yr−1. The effects of viscosity contrasts across the model domain are assessed in terms of their impact on baseline variations and strain rates