The Role of Data Processing and Uncertainty Management in Seismic Hazard Evaluations: Insights from Estimates in the Garfagnana–Lunigiana Area (Northern Italy)

Significantly different estimates of seismic hazard may result for the same site as aneffect of different methodological choices underlying the adopted procedures. In orderto explore this aspect, two approaches devoted to probabilistic seismic hazard assessment are considered for the evaluation of hazard in a seismic area in Northern Italy. In particular, results of a standard procedure are compared with those obtained by an innovative approach. Fundamental features of this last methodology are the extensive use of intensity data relative to seismic effects observed at the site of interest during past earthquakes and the basic role attributed to the parameterisation of uncertainty which affects the considered pieces ofinformation. The analysis indicates that the new approach supplies results significantlydifferent from those obtained from standard methodology and that these differences strongly depend on strategies adopted for data processing and for the management of uncertainties which affect input parameters.