Statistical occurrence analysis and spatio-temporal distribution of earthquakes in the Apennines (Italy)

We present two examples of statistical analysis of seismicity conducted by integrating geological, geophysical and seismological data with the aim to characterize the active stress field and to define the spatio-temporal distribution of large earthquakes. Moreover, our data will help to improve the knowledge of the "seismogenic behavior" of the areas and to provide useful information for seismic hazard evaluation. The earthquakes are described by two non-parametric statistical procedures integrating also tectonic-physical parameters to study the spatio-temporal variability. The results show that the areas are characterized by: 1) a stress regime with mainly extensional kinematics; 2) tectonic structures mainly oriented with the active stress field (S-hmin=N44 degrees +/- 18 degrees in the southern Apennines and S-hmin=N50 degrees +/- 17 degrees in the central Apennines); 3) cluster distribution of seismicity and 4) a high probability of earthquake occurrence (M > 5.5) in the next 10 years. (c) 2007 Elsevier B.V. All rights reserved.