Seismic velocity structures of Southern Italy from tomographic imaging of the Ionian slab and petrological inferences

In this study we have determined detailed Vp and Vs seismic velocity models of the Ionianlithosphere subducting beneath the Tyrrhenian basin and of the surrounding mantle, by applyinga post-processing technique to a large sample of local earthquake tomography studies.Our seismic velocity models permit us to infer the presence of low velocity anomalieswithin the slab, which we interpret as regions that are partially hydrated by fluids releasedduring the subduction process. A petrological interpretation of the velocity anomalies givesnew details on the magmatism of the volcanic Aeolian arc. Furthermore our velocity modelsprovide a more detailed description of the boundary of the slab and its connection with the largeseismically active Tindari-Letojanni strike slip system. Finally these results allow describingin detail some features of the slab as the presence of lateral and vertical tears. In conclusion,the obtained models provide some constraints for inferences on mantle circulation, and on thegeodynamical evolution of the central-western Mediterranean.