GNGTS 2013 - Atti del 32° Convegno Nazionale

end, the ISIDE database is used; http://iside.rm.ingv.it ). The catalog collects both historical [the CPTI04 catalog is used (Gruppo di Lavoro CPTI, 2004)] and instrumental earthquake data. Note, finally, that a Monte Carlo simulation procedure is adopted to allow for the uncertainty affecting earthquake magnitude and seismogenic thickness. Strain rate maps presented here display average results from 500 randomizations. For further details regarding the overall procedure, the reader can refer to the article of Barani et al. (2010). Results and discussion. Fig. 2 shows the distribution of the seismic strain rate values before (Fig. 2a) and after (Figs. 2b and 2c) the 2012 sequence. While the maps in Figs. 2a and 2b are based on earthquake data sets collecting independent events [analogously to Barani et al. (2010)], Fig. 2c includes also the contribution of aftershocks and foreshocks recorded between year 2007 and 2013. Compared to the map in Fig. 1, the maps in Fig. 2 are computed using a finer grid, of 0.025° spacing in latitude and longitude. Comparing the three maps not only seems to confirm our suspicion about the presence of a seismicity gap (precisely, a spatial gap) between Modena and Ferrara but would also indicate that this gap was completely filled in by 2012 crisis. Note the non-negligible contribution from the stronger aftershocks following Fig. 2 – Comparison of seismic strain rate distributions before (a) and after (b and c) the 2012 Emilia crisis. The maps in Figs. 2a and 2b use declustered catalogs. Clusters from year 2007 to 2013 are retained to produce the map in Fig. 3c. Red circles indicate M5.5+ earthquakes occurred since 1740 (year of completeness for M5.5+ events). The major events belonging to the 2012 sequence are indicated by red stars. 212 GNGTS 2013 S essione 1.2