Investigating seismogenic faults in Central and Southern Apennines (Italy): modeling of fault-related landscape features

Abstract

The direct identification of seismogenic structures in Southern Italy is often a difficult task, since finding seismogenic faults with clear surface expression associated is unlikely, even if they are the source of large magnitude earthquakes. A possible way to solve this problem is the investigation of a series of features of the surface landscape that could be attributed to repeated movements along a fault. In this paper we investigated the drainage, ancient coastlines, marine terraces and recent deposits of three different active tectonic basins in central and Southern Italy. The combination of the modeling of these fault-related landscape features with historical and seismological data better constrained the geometry of the seismogenic faults responsible for three large magnitude historical events in the studied areas. The results show that in this section of the peninsula seismogenesis is often connected with blind almost pure dip-slip normal faults; the long-term activity of these faults produces intermontane basins or coastal plains that are sinking relative to the surrounding areas; the application of this methodology emphasises the importance of geological and geomorphological studies for the recognition of seismogenic faults and for a complete assessment of the seismic hazard in Italy.