hide
Free keywords:
GNSS CEGRN Dense GNSS network EPN ETRF2000 Tectonic structures Velocity profile
Abstract:
Based on a set of rigorously computed velocities of GNSS (Global Navigation Satellite Systems) sites of the CEGRN (Central European GNSS Research Network) we identify a number of areas with large scale tectonic structures and interpolate the velocities to the profiles by least squares collocation. The resulting velocity field provides an invaluable data set for the investigation of present day crustal deformation at the continental scale. We present six velocity profiles covering structural features of Central Eastern Europe and at the same time well populated by GNSS sites, to minimize interpolation errors. One N-S profile samples the stretching of the crust in the Balkan-Aegean region, three E-W profiles sample the part of Central Europe north of the Black Sea, one SW-NE profile crosses the Trans European Suture Zone. A sixth profile outlines the shear deformation associated with the eastward extrusion of the Eastern Alps towards the Pannonian Basin. Analytical modelling of the first and last profiles, for which there is a significant deformation, provides quantitative constraints on the relation between back arc retreat and extensional deformation in the continental crust (Aegean-Balkan profile), and model parameters such as the locking depth of faults accommodating the lateral extrusion of the Eastern Alps. For the four remaining profiles, across the TESZ and the Central Europe through the Carpathians, we report a westward velocity East of the TESZ and Carpathians. The velocities appear to drop West of these structures, suggesting that in a conventional ‘European fixed’ reference frame the East European Craton is generating a small compressional strain in a nearly E-W direction. We show by analytical modelling in an elastic half space that this compression can be accommodated by slip between 8 and 25 mm/yr along fault planes at crustal depths and aligned to the Carpathian orogeny.
