Surface kinematics in the Alpine-Carpathian-Dinaric and Balkan region inferred from a new multi-network GPS combination solution

The understanding of the intraplate tectonics of Central Europe requires a detailed picture of howstress is transferred from the interaction of the Eurasian, Nubian and Anatolian plates to the Alpine, Carpathian, Pannonian and Dinaric regions. Recent strain distribution is controlled by the Adria horizontal push, by the Vrancea vertical slab pull and associated horizontal displacements, and by the Aegean/Anatolia extension and slab-roll back. We present a horizontal velocity field for the Alpine-Carpathian-Pannonic-Dinaric and Balkan regions resulting from a new combination of seven different GPS networks formed from permanent and campaign stations. Dedicated velocity profiles in two specific regions are studied in detail. One is the Alpine Pannonian region,with a detailed picture of the NS indentation of the Adriamicroplate into the Southern Alps, inNE Italy, the deformation in the Tauern Windowand the eastwards kinematics of a Pannonian plate fragment. The second study region includes Transylvania, the Southern Carpathians upto theAegean sea and Albania, where amajor right lateral shear deformation exists as a consequence of theNE convergence of the Apulia platform towards the Dinarids, and theSSWmotion of Macedonia,Western Bulgaria and Rumania, related to theHellenic arc dynamics in the EasternMediterranean. The profiles in the Alpine–Pannonian area indicate that a velocity drop of 2.5+/−0.4 mm/yr associated with the Adria indentation concentrates on a segment of some 50 kmsouth of the Periadriatic fault. The deformation becomes extensional by a similar amount just north of the Periadriatic fault, in the Tauern Window, where the updoming of the Tauern Window implies vertical motionwhich couldwell be associatedwith surface extension. In theEWprofile,we observe a sudden velocity change of 1.5+/−0.2 mm/yr in 20 km, corresponding to the right lateral Lavant fault, which seems to mark the border between dominant indentation kinematics to theWest and dominant extrusion kinematics to the East. Three profiles are considered in Southern and Eastern Europe: one across the lower Adriatic sea fromApulia in Italy to the southern Dinarides, which enables it to constrain the velocity drop associated with the subduction of the Adria microplate into the Dinarides to 3.2+/−0.5 mm/yr in 140 km. The second profile is longitudinal and constrains the velocity inversion of 7.4+/−1.0 mm/yr in 350 km associated with right lateral shear faults in Albania. The third profile crosses the Transylvania region with a shortening of 2.3+/−1.0 mm/yr in 220 km, and the Wallachian– Moesian region up to the Chalcidic peninsula in NGreece. This lower part of the profile implies an extensional stretch of the upper crust of 3.2+/−0.9 mm/yr in 440 km, culminating in the Hellenic arc. Strain rate maps are presented in this regional scale, showing the excellent agreement between fault plane solutions of crustal earthquakes and the eigenvectors of the GPS derived two dimensional strain rate tensor.