Looking for missing earthquake traces in the Ferrara-Modena plain: an update on historical seismicity

Abstract

The area most affected by the May-June 2012 Emilia sequence has a centuries-old seismic history with comparatively moderate maximum magnitude values, on a par with those on record in the nearby Reggiano-Parmense area but less significant than those known to occur in the northern Apennines and greatly lower than those on record in the most seismically active zones of the Italian peninsula. According to the latest issue of the Italian seismic catalogue (Rovida et al., 2011) Mw~5.5 earthquakes are known to have occurred near Ferrara (1346, 1561) and in the areas of Finale Emilia-Bondeno (1574, 1908, 1986), Mantua (1901) and Cento (1922). This picture might be incomplete, as suggested by the recent discovery of a previously unknown earthquake occurred in 1639 with I max 7-8 MCS in Finale Emilia (Camassi et al., 2011b).The incompleteness of the current picture of local seismicity is shown by a number of previously unknown, moderately damaging local earthquakes retrieved by recent studies: a few particularly interesting cases are described.