3D thermo-mechanical simulations of the Mediterranean show what controls the motion of Adria

The motion of the Adriatic microplate is thought to be highly sensitive to the surrounding subduction zones and the convergence of Africa and Eurasia. However, our understanding of mantle dynamics in the Mediterranean region and its effect on plate motion remains incomplete. Here, we present the results of several hundred, high-resolution 3D visco-elasto-plastic thermo-mechanical models of the entire Mediterranean region. The simulations start from plate tectonic reconstructions and simulate the geodynamic evolution over the last 35 Myr. They take the convergence of the African and Arabian plates with the Eurasian plate into account, along with the dynamics of the subduction systems in the western (Apennines-Calabria), central (Dinarides-Hellenides) Mediterranean, and in the Alpine-Carpathian region. The simulations give insights into the parameters that determine the motion of the Adriatic microplate. Our results demonstrate that the subduction systems around Adria are highly coupled, which gives rise to complex asthenospheric flow in the central Mediterranean. Three factors are of key importance: 1) the convergence between the African and Eurasian plates, 2) the retreat of the Alpine subduction zone to the north of Adria, and 3) the distance between the Calabrian and Hellenic subduction zones around Adria. Furthermore, in a system characterized by active convergence between Africa and Eurasia, the slab pull exerted by nearby subduction zones can only notably influence the motion of the Adriatic microplate if these subduction zones are located within a few hundred kilometers of Adria.