GNGTS 2013 - Atti del 32° Convegno Nazionale

We suggest instead that the choice of the criteria to be used for seismic risk mitigation should be made by paying great attention to all past strong earthquakes, even though remote and not frequent, and to the ongoing tectonic setting. In fact, considering that the timing of the next dangerous shocks can hardly be inferred by the available seismic history, we should concentrate our efforts in trying an estimate of the maximum seismic potential of the fault systems involved. In line with this concept, we have replaced the seismic zones adopted by PSHA (which have been mainly defined in a way to make the resulting seismicity data set matching the assumptions of the statistical analysis) with new zones more compatible with the seismotectonic context. Fig. 3 – Maps of I max proposed for the commun e s of Tuscany and Emilia-Romagna (Mantovani et al. , 2012, 2013). The comparison of this map with the one shown in Fig. 1 points out the considerable variations produced by adopting our procedure instead of the PSHA one. 426 GNGTS 2013 S essione 2.3