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Neo-deterministic seismic hazard assessment (NDSHA) is based on the geophysical and seismotectonic features of a region and adopts a multiscale approach (i.e., regional and local) and multiscenario approach. This methodology has been successfully applied to many regions worldwide and, for the purpose of seismic microzoning, to several urban areas, including lifelines, relevant buildings, and cultural heritage sites. NDSHA naturally supplies realistic time series of ground motion, including reliable estimates of ground displacement readily applicable to seismic isolation techniques, useful to preserve historical monuments and relevant man-made structures. In this way, it creates a viable bridge between the seismological and the engineering community. We discuss here its application to the cities of Rome (where the first seismic microzonation study was developed using NDSHA), Valparaiso (where one of the first multihazard study was developed), and Trieste (where the first NDSHA study for seismic verification was conducted). This contribution should be intended as a sort of an illustrative, but definitely not exhaustive, view in space and time through possible NDSHA applications at a local scale.

In recent years, probabilistic seismic hazard assessment (PSHA) has been the most common procedure to evaluate the potential effects of future earthquakes. It assesses the probability that some measure of ground motion intensity (e.g., the peak ground acceleration) exceeds some threshold during a given period of time (most commonly 10% in 50 years’time). In Europe and the Mediterranean region, different efforts starting in the 1990s have provided several regional hazard models at the continental scale (e.g., Jiménez et al., 1999, 2001; Giardini et al., 2003) with the latest model in Woessner et al. (2015) deriving a complete set of harmonized seismic hazard results and associated uncertainties for Europe. Site studies for nuclear power plants were the onset for the development of seismic hazard in Spain at the beginning of the 1970s. At that time, the existing regulations demanded classical deterministic analysis. Therefore, only a few works included either statistical or probabilistic approaches, which later on were widely applied in most of the regional hazard studies carried out in Spain in the 1980s and 1990s (see, e.g., Martín, 1984; Muñoz et al., 1984; Litehiser and Marrone, 1991, among others). It was for the first time in 1994 when the update of the Spanish Building Code incorporated a probabilistic seismic hazard map to define the basic seismic action (Martín, 1995). Studies incorporating alternative statistical analysis, including Bayesian techniques, of hazard parameters were also applied in the last 1980s and early 1990s (see, e.g., García-Fernández et al., 1989; Egozcue et al., 1991)