GNGTS 2016 - Atti del 35° Convegno Nazionale

108 GNGTS 2016 S essione 1.1 The February 20, 1743 earthquake is considered the strongest seismic event occurred in the area in the last centuries, over a seismic period that began in 1741 (Margottini, 1985; Guidoboni et al. , 2007; Galli et al. , 2008). The event was felt in the whole Apulia region, in many cities as Napoli, Matera, Reggio Calabria, Messina in southern Italy, and even in some localities of Central and Northern Italy as Parma, Venezia, Vicenza, Trento and Udine, the last two cities far from the epicentral area more than a thousand kilometres. This earthquake was also felt in a wide sector of the Mediterranean area along the western coast of Greece, Albania and on Malta islands. It also generated massive environmental effects as a large tsunami (Mastronuzzi et al. , 2007; Maramai et al. , 2014). On the basis of the collected documentary and historical sources, together with the geomorphologic evidences of the earthquake environmental effects, the re-evaluation of the 1743 seismic event has been carried out, according to the ESI-07 scale (Michetti et al. , 2007), assessing epicentral intensity I 0 =XI and magnitude Mw≥7.1 (Nappi et al. , 2016). The instrumental seismicity in the Murge and in the Salento peninsula is characterized by scattered seismicity of low energy, mainly concentrated in the western sector of Salento, in the Gulf of Taranto and in the Otranto channel. In particular in the Gulf of Taranto moderate energy events with epicenters not far from the coasts of Salento have occurred, as in the case of the May 7, 1983 earthquake (Mw=5.0) (Tab. 1). Moreover, the area of the Otranto channel Tab. 1 – Historical and recent earthquakes occurred in the Salento peninsula and surrounding seas extracted from CPTI04 (Gruppo di lavoro CPTI 2004), CPTI11 (Rovida et al. , 2011, 2016), CFTI4Med (Guidoboni et al. , 2007).