Models and issues in history-dependent mainshock hazard

The purpose of this paper is to critically review some history - dependent probabilistic mainshoc k occurrence models with respect to probabilistic seismic hazard analysis (PSHA) . In PSHA , eart h- quake occurrence is usually referred to homogeneous Poisson process (HPP) , which is memory - less ; h owe v- er, when a single fault is of concern and/or the time scal e is different from that of the long term, history - dependent models, may be appropriate. In the study, two categories of models are reviewed : (i) renewal pr o- cesses , which are used to model the sequence of interarrival times of characteristic earthquakes , a nd (ii) si m- ple M arkov renewal processes , in which beyond earthquake occurrence, modeling of correlation between magnitude and interarrival time is also explicitly addressed . As an illustrative application, the Paganica fault (in central Italy) is considere d to compute the seismic hazard , in terms of exceedance pro b ability of a ground motion intensity measure value , according to each of the models rendered comparable by means of working hypotheses . Results show that as larger is the time since the last earth quake the more different hazard is i m- plied by the different models , rendering critical their selection for sources where the time since the last event is large .