Integrated Neodeterministic Scenarios for Reliable Earthquake Hazard Assessment

We integrate a) the intermediate-term medium-range earthquake predictions with the procedures developed for b) the recognition of strong earthquake prone areas and c) for the Neo-deterministic assessment of seismic hazard. We associate the alarms declared by the prediction algorithms to a set of possible seismic ground motion scenarios: the seismological and morphostructural analysis permit to define the “Scenario Earthquakes”, i.e. the strong events that could affect a selected area, that can be used by the Neo-deterministic analysis, able to realistically model the seismic input at a given site. Where the synthetic seismograms can be successfully compared with the recorded signals or with the macroseismic data, the theoretical estimates allow us to produce reliable microzonation maps, consistent with the set of possible scenario earthquakes. We supply, for several cities in Italy, examples of scenarios for events with M≥6.5, that turn out to be the closest impending events. The time information given by the intermediate-term medium-range earthquake prediction is very useful to plan preparedness and rescue actions and to define priority criteria for the investigations required by the seismic microzonation. Even if strong motion records in near-fault, soft soil, or basin conditions have been recently obtained, their number is still very limited to be statistically significant for seismic engineering applications: realistic ground motion modelling is now the only viable tool for effective prevention purposes.