Control of shelf width on submarine canyon formation along the central Algerian margin

Erosive dynamics in deep marine environments are strongly controlled by the morphology of the continental shelf, particularly along active margins. On the central Algerian margin, where shelf width varies laterally, submarine incision manifests through the co-development of deeply incised canyons and dense gully networks. This study investigates how shelf width influences the formation, spatial distribution, and evolution of these erosive features, based on high-resolution bathymetric data acquired during the MARADJA 1 cruise (2003) and through detailed morphometric analyses. The results reveal that in areas where the continental shelf is narrow (5_20 km), gravitational processes are highly focused, promoting the development of deeply incised canyons characterized by steep slopes, smooth longitudinal profiles, and hierarchical drainage networks. Conversely, wider shelf areas (30_40 km) facilítate a gradual dissipation of sedimentary energy, leading to the formation of dense but shallow gully networks, organized in a less hierarchical pattern. The spatial distribution of these erosive forms suggests that shelf width acts as a morphological filter, controlling sediment transfer pathways to the slope and deep basin. These findings provide new insights into the geomorphological processes shaping the evolution of continental margins and highlight the critical role of morphological parameters in modeling sediment transfer and assessing associated geological hazards, such as submarine landslides and tsunamis.