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 Ionian
lithosphere subducting beneath the Tyrrhenian basin and of the surrounding mantle, by applying
a 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 anomalies
within the slab, which we interpret as regions that are partially hydrated by fluids released
during the subduction process. A petrological interpretation of the velocity anomalies gives
new details on the magmatism of the volcanic Aeolian arc. Furthermore our velocity models
provide a more detailed description of the boundary of the slab and its connection with the large
seismically active Tindari-Letojanni strike slip system. Finally these results allow describing
in 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 the
geodynamical evolution of the central-western Mediterranean.