Earthquake environmental effects induced by the 2012 seismic sequence in Emilia: implications for seismic hazard assessment in Northern Italy

The field characterization of Earthquake Environmental Effects occurred in the epicentral area of the 2012 Emilia seismic sequence (mainly liquefaction-type phenomena, ground fractures and hydrological anomalies) has allowed i) to identify in the affected area the zones more susceptible to local geological instability and ii) to make an independent intensity assessment through the ESI 2007 intensity scale. The distribution of ground effects is suggestive of two events of Intensity VIII, even if the maximum intensity might have been even higher (IX?) in San Carlo and Mirabello. Nevertheless, the estimated intensity of the 2012 Emilia earthquake is sensibly less than that recorded in the Po Plain area in historical times (I0 IX to X), and therefore should not be considered the “reference earthquake” for this area