Geological criteria for evaluating seismicity: lessons learned from the Po Plain, Northern Italy

We compare available literature and new geological and paleoseismological data, in particular from the Monte Netto - Brescia site, to maintain that A) strong earthquakes similar to the intensity IX to X MCS - M6.5 to 7 - historical events occurred in 1117 and 1222, though very rare, must be considered unlikely but credible events along virtually all the Quaternary faults throughout the whole Po Plain Foredeep, at least until we learn from geological and geophysical studies how/if the Quaternary tectonic structures near Lake Garda are truly different from those in other areas such as, for example, the Turin Hills, Monferrato, Insubria or around Piacenza, B) the late Quaternary (and especially Holocene) history of deformation and the local seismic landscape are far more valuable tools in estimating seismic hazard than has generally been appreciated until now in Italy - as well as in most parts of the world. The lack of significant earthquakes for 8 centuries in the Garda region and for longer elsewhere must prompt an effort to much deeper understanding of the actual seismic potential in one of the most populated and economically developed areas of Europe.