Widespread mass-wasting processes off NE Sicily (Italy): insights from morpho-bathymetric analysis

The NE Sicilian continental margin is largely affected by canyons and related landslide scars. Two main types of submarine canyons are recognizable: the first type carves the shelf up to depths <20 m, a few hundred metres from the coast, acting as a main collector for sediments transported by hyperpycnal flows and/or littoral drift. These canyons mostly have a V-shaped cross-section and are characterized by a strong axial incision, where a network of dendritic gullies carving the canyon flanks converges. The second type of canyon occurs where the shelf is wider, hindering the direct connection between the subaerial and submarine drainage system. This setting exhibits canyon heads mostly confined to the shelf break, characterized by a weaker axial incision of the canyon and U-shaped cross-section. A total of 280 landslide scars are recognized in the study area and these are divided into three groups according to their morphology and location. A morphometric analysis of these scars is performed to investigate which parameters might be key factors in controlling instability processes and how they correlate with each other. We also try to assess the possible tsunamigenic potential associated with these landslide events by coupling the morphometric analysis with semi-empirical relationships available in the literature.