Imaging the velocity structure of the Calabrian Arc region (southern Italy) through the integration of different seismological data

Abstract

We present a new 3D, P-wave velocity model of the crust and upper lithosphere for the Calabrian Arc region. The model results from integration of different types of seismic velocity data available in the literature, following a method conceptually similar to one that has been successfully applied in the Alpine region. The model obtained, clearly shows the first-order structural features of the area, in agreement with the complex puzzle of lithospheric units. It also has the advantage of representing the simplest velocity structure that is consistent with all published data. We then employed this “apriori” velocity model as starting model for a local earthquake tomography. The velocity pattern obtained furnishes new information on the relationships between deep dynamics related to the Ionian subduction system and processes occurring at crustal depths. In addition, also the low RMS values coming from hypocenter locations indicate an improvement with respect to 3D models already available and to tomographic results obtained by testing different starting velocity models.