Seismicity, seismotectonics and seismic hazard of Italy

A first generation of probabilistic seismic hazard maps of the Italian coun try are presented. They are based on seismogenic zoning deriving from a kin ematic model of the structural tectonic units and on an earthquake catalogu e with the foreshock and aftershock events filtered out. The following grou nd motion parameters have been investigated and mapped using attenuation eq uations based on strong-motion recordings of Italian earthquakes: peak grou nd acceleration and velocity; Arias intensity; strong motion duration; and the pseudovelocity and pseudoacceleration spectral values at 14 fixed frequ encies both for the vertical and the largest horizontal component. A Poisso nian model of earthquake occurrence is assumed as a default and the hazard maps are presented in terms of ground motion values expected to be exceeded at a 10% probability level in 50 years (return period 475 years) according to the requirement of Eurocode 8 for the seismic classification of nationa l territories, as well as in terms of exceedance probabilities of selected ground motion values. Finally, as a tentative study, the use of hybrid meth ods (implementing both seismogenic zones and structures), renewal processes (including earthquake forecasting) and the influence of site effects (as t he basis for the planning of earthquake scenarios) were explored. (C) 2000 Elsevier Science B.V. All rights reserved.