Lithosphere Dynamics in the South-Central Mediterranean (Sicily-Calabria)

Within the Mediterranean realm, the geodynamic setting of the Sicily-Calabria region is controlled by a combination of two main components: the large scale Africa-Eurasia convergence and the ESE retreat of the Calabrian subduction zone. The interaction of these two is complex and probably distinctly non-stationary. For the Sicily-Calabria region, multi-disciplinary data have shown that the two, distinctly identified fault systems in the Ionian basin, the Alfeo-Etna and Ionian faults, play different roles, predominantly in accommodating Africa-Europe plate convergence and slab rollback, respectively. Using data on present-day deformation (GPS data and distribution of faults) and numerical modeling techniques, we aim to increase understanding of the complex interaction process by establishing a quantitative integrated model based on the active tectonic forces. A key element of this model is the quantification of fault slip along major faults zones in the region. In this way, we focus on two points: 1) the magnitude and direction of the longer term (few Mys) regional tectonic forces, with the potential to hindcast geological deformation, and 2) quantification of shorter term fault slip (highly non-uniform in the region) along major fault zones by investigating which faults are active, temporarily locked or inactive at Present, with the potential for understanding seismic hazard. We find that lithospheric body forces are important in this region of complex tectonic interaction, driving extension in an overall convergence setting. Predicted fault kinematics indicate that convergence is accommodated at the Sicily-Tyrrhenian offshore thrust front, extending eastward to the Tindari-Ionian (STEP) fault, while STEP faults allow for ongoing arc migration, with low-magnitude coupling at the subduction contact.