THE GARGANO PROMONTORY - AN IMPORTANT ITALIAN SEISMOGENIC TSUNAMIGENIC AREA

Gargano is a small mountainous promontory protruding into the Southern Adriatic and, from a structural point of view, it is part of the Apul ia foreland. Deformative structures, both inland and offshore the prom ontory, are quite common and can partially be associated with a substa ntial Quaternary uplifting. Seismogenically this area is well known, b ecause several historical strong earthquakes have been reported to occ ur here and recent important seismic sequences have been recorded. Thi s paper is a contribution to evaluate the seismogenic as well as the t sunamigenic potential of this region. Particular attention has been gi ven to study the major events, some of which were able to produce tsun amis. The epicenter location of some of these earthquakes computed sol ely on the basis of macroseismic data would point to focal regions on land, but this is questionable if tsunami generation is taken into acc ount. As regards the tsunamigenic potential, statistical analysis is u sed to evaluate the local geographical distribution of expected tsunam is and the mean return periods. It is found that large events are expe cted on average every 228 years, while a tsunami of any size is genera ted every about 84 years, which is in good agreement with the experime ntal observations.