Integrated geophysical investigations for seismic zoning in a coastal area of Northern Sicily

The area, about 225 km2 large, ranging from the Eleuterio river to the S. Leonardo river on the northern coast of Sicily, has suffered many earthquakes in the past centuries and has for many years recognized as a seismic area. This paper presents a set of integrated geophysical studies carried out in that area, including: i) a statistical study of the past earthquakes in order to define the earthquake risk (PGV or PGA risk), ii) a set of laboratory density measurements carried out on samples of rocks (82 samples), Hi) a shallow refraction investigation (290 profiles) in order to study the mechanical properties of such rocks, iv) a deep geoelectrical investigation (200 VES) in order to reconstruct the main geological features with particular regard to the geometrical distribution of the elastic and plastic formations which have been piled up during the complex overthrusting of the Sicilian chain, and v) a detailed study of the possible amplifications of the groundmotions due to the geometry and the mechanical characteristics of the shallow and intermediate rocks. The results, combined wih the knowledge of the regional tectonic features and the locations of the involved seismogenetic volumes, allow the formation of a picture of the seismic responses and the connected seismic risk