Abstract 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.

Abstract The collection of high-resolution multibeam bathymetry off the tectonically controlled Tyrrhenian Calabrian margin (southern Tyrrhenian Sea) allowed us to recognize several mass-wasting processes, including shelf-indenting canyons and several landslide scars ranging over different spatial scales. In this paper, we aim to characterize two large submarine landslides (S1 and S2) affecting an area of c. 7 and 14 km 2 , respectively; both scars occur within water depths of 700–1000 m on slope gradients of 1.5−3°. S1 is interpreted as a disintegrative landslide, because most parts of the related landslide deposits were evacuated from the scar and are not recognizable on the present-day bathymetry, whereas the landslide deposits of S2 are well-preserved and mostly confined within the scar, indicating a different post-failure evolution. Based on the integration of multibeam bathymetry and single-channel seismic profiles, both the landslides are interpreted as translational failures, whereas their different post-failure behaviour has been associated with differences in material properties (inferred by headscarp morphology), depth of their failure plane and frontal confinement. We also suggest that thick contourite deposits recognized in the area may represent an important preconditioning factor for the development of these landslides, similarly to that observed in the nearby Capo Vaticano scar complex.

Abstract This paper documents the Late Quaternary (120 ka BP–present) stratigraphic architecture of Italian continental shelves through the interpretation of single-channel, very high-resolution seismic reflection profiles and from data derived from published studies, by using the high-resolution sequence stratigraphy framework. The result of this analysis provides a detailed reconstruction of the variability of shelf stratigraphy in relation to differences in physiography, sediment supply, structural framework and local factors. We distinguish four stratigraphic types: (1) wide shelves with high sediment supply (e.g. the central Adriatic and the central-northern Tyrrhenian shelves); (2) wide but sediment-starved shelves (e.g. the southern Latium shelf); (3) narrow shelves with high sediment supply (e.g. shelves located in the Ionian and southern Tyrrhenian Sea); and (4) narrow and sediment-starved shelves (shelves located around islands and archipelagos). Besides physiography, sediment supply and vertical movements, local factors and specific processes play a significant role in determining Late Quaternary stratal architecture and sedimentary facies. For example, the attributes of antecedent topography commonly seem to govern the formation and preservation of transgressive deposits, whereas the formation and preservation of falling stage and lowstand systems deposits can be hindered by the presence of canyons indenting the shelf edge and/or slope instability.