Defining a model of 3D seismogenic sources for Seismic Hazard Assessment applications: The case of central Apennines (Italy)

摘要: Geology-based methods for Probabilistic Seismic Hazard Assessment (PSHA) have been developing in Italy. These require information on the geometric, kinematic and energetic parameters of major seismogenic faults. In this paper, we define a model 3D sources central Apennines Our approach is mainly structural-seismotectonic: integrate surface geology data (trace active faults, i.e. 2D features) with seismicity subsurface geological–geophysical (3D approach). A fundamental step to fix constraints thickness layer deep geometry faults: use from depth distribution aftershock zones background seismicity; also structural style extensional deformation at crustal scale (mainly seismic reflection data), as well strength behaviour (brittle versus plastic) crust by rheological profiling. Geological observations allow us segmentation consisting fault structures separated first-order (kilometric scale) structural-geometric complexities considered likely barriers propagation earthquake ruptures. Once defined features model, onward computation maximum magnitude expected (Mmax). We compare three different estimates Mmax: (1) association past earthquakes faults; (2) (3) geometrical estimate ‘corrected’ scaling laws. By integrating all data, (seismogenic boxes), which can be directly used regional-scale PSHA. Preliminary applications PSHA indicate that may hazard scenarios more realistic than those previously proposed.