Surface Faulting Hazard in Italy: Towards a First Assessment Based on the ITHACA Database

The Italian territory is characterized by a great number of capable faults (i.e., faults able to produce significant ruptures/deformations at or near the surface). However, the potential of tectonic surface rupture/deformation (Surface Faulting Hazard, SFH) is not properly considered in national seismic hazard maps and legislation. In this paper it is proposed an assessment of SFH in Italy based on the ITHACA database, where the shape and width along capable faults as well as maximum expected surface displacements are defined in function of the seismotectonic behaviour and the severity of maximum expected earthquake. The proposed assessment indicates where SFH is expected to be relevant. In this sense, it is an helpful tool for site selection of critical facilities but also for ordinary land planning. Of course, the evaluation of SFH at local scale in the setback areas requires a more detailed characterization through ad hoc seismotectonic and paleoseismic investigations.