GNGTS 2014 - Atti del 33° Convegno Nazionale

102 GNGTS 2014 S essione 1.1 localities. Moreover we have evaluated the most important effects on land in the Salento area due to the strong earthquakes of northern Apulia, southern Apennines, Adriatic and Ionian sea, Albania and Greece. The use of both traditional MCS macroseismic intensity scale and the ESI 2007 scale gives a more accurate image of the earthquake (Dengler and McPherson, 1993; Porfido et al. , 2007; Serva et al. , 2007) and allowed us to better constrain the seismic hazard assessment in the Salento peninsula. Geodynamic background. The central area of the Mediterranean basin is a plate-boundary region of high seismicity and complex tectonics, dominated by frequent earthquake activity occurring mostly in the Ionian Sea and western Greece. The Apulia region, NW-SE elongated, represents the emerged part of the Adriatic foreland domain shared by the Apennine chain to the west, and the Dinaride-Hellenide chain to the east (Moretti and Royden, 1988). The geodynamic background of this area is characterized by the ongoing subduction of the Ionian slab beneath the Calabrian Arc (Caputo et al. , 1970), such compressional regime is still active and outlined by relevant seismicity (Castello et al. , 2006). As regards the tectonic setting of theApennine-Dinaride converging region and surroundings, according to Gambini and Tozzi (1996) the major structural lineaments to be considered are: the Scutari-Pec Line; the Pescara-Dubrovnik dextral shear Line ; the North Gargano Fault Zone; the Mattinata Gondola Fault Zone; the South Salento-North Kerkira Fault Zone; the right-lateral Cephalonia Transform Fault (see map in Gambini and Tozzi, 1996). The rigid Apulian foreland block has been deformed through several normal faults, NW-SE and NNW-SSE trending, some of them presently active since they dislocate the sea floor by about 200–300 m (Merlini et al. , 2000); moreover, major E-W strike-slip and oblique-slip fault zones divide Apulia into structural blocks behaving independently, among them the Gargano Promontory, the Murge Ridge and the Salento Peninsula are relevant. In particular, the Salento peninsula represents the southernmost part of the Apulia foreland. The outcropping rocks are prevalently limestone-dolomite units belonging to the Apulia platform, with carbonatic- terrigenous marine deposits at the top of the stratigraphic sequence, Middle Eocene-Upper Pleistocene age (Mastronuzzi et al. , 2011). The Salento peninsula has undergone a general uplift since Middle Pleistocene, with total amount of about 150 m; after this period and in more recent times, neotectonic data indicate a significant stability of this area. Seismicity of the area. Apulia is a region with relatively moderate seismicity surrounded by regions with destructive seismicity: to the east the coast of Albania and the Ionian Islands (western Greece); to the west the Calabrian arc and the southern Apennines chain ����� �� ������� (Fig. 1) (Slejko et al. , 1999). The northern part of the Apulia region is characterized by higher energy earthquakes than the southern Fig. 1 – The map shows the spatial distribution of historical and recent seismicity extracted from: CPTI11 (Rovida et al. , 2011), red squares; SHEEC (Stucchi et al. , 2013) yellow dots (Grünthal et al. , 2013) blue squares. In grey the composite seismogenetic sources (Basili et al. , 2013).