The seismogenic thickness in Italy: constraints on potential magnitude and seismic hazard

Abstract

The thickness of the seismogenic layer is a key parameter for seismic hazard, since it can be used to constrain the maxi- mum depth of faulting and the potential magnitude. In this study, we compute the seismogenic thickness in the Italian region by defining the lower seismicity cut-off, using high- quality hypocentral locations of earthquakes that occurred in the past decade. Along the eastern Alps, the seismogenic thickness is about 12–14 km, laterally homogeneous along the entire south-verging thrust front. In the Apennines exten- sional belt, lateral changes in seismogenic thickness are evi- dent, and correlate with changes in the seismic energy released by past earthquakes. The potential magnitude is lar- ger in the southern Apennines where the seismogenic thick- ness is greater (16–18 km) than in the northern Apennines where it is less (6–10 km) and seismic energy is partially released by the creeping of faults