Seismotectonics of Southern Calabria Terrane (South Italy)

Abstract

Seismic data of earthquakes recorded during the last 40 years in southern Calabria have been compared with geological data in order to obtain a seismotectonic picture of the area. We sought for any possible correlation between the main regional tectonic st ructures, the distribution of earthquake hypocentres and the focal mechanism of earthquakes with magnitude (Ml)≥3. Studies of historical and recent seismicity and analysis of geological stru ctures allowed to define the main shear strips on a regional scale. More than 2600 earthquakes with 1.5 ≤ Ml ≤ 4.5 have been considered. The focal mechanisms of earthquakes with Ml≥3 have been compared with the kinematics of known faults and used to give insight on the current active stress field. From the analysis carried out it was possible to expand the cognitive framework regarding the activity of the main tectonic structures present in the area. This study also served to identify areas of high seismicity which do not correspond to any evidence of tectonic structures on the surface, and areas where recognized tectonic structures have not shown any seismicity during the la st decades. These cases could be the subject of future investigation in order to correctly assess the se ismic hazard in Calabria. This task is important in the context of seismic hazard evaluation and mitigation.