Bedforms of the Mediterranean outflow current generated at the exit of the Strait of Gibraltar

Abstract

The effects of the Mediterranean Outflow Water (MOW) over a deep seafloor environment have been filmed with an ARGUS ROV system in the Cadiz Contourite Depositional System (Gulf of Cadiz, Spanish Atlantic). The new images, obtained in different erosional and depositional features of the system at depths between 500 and 700 m, state the capability of bottom currents to generate bedforms at different scales. The ROV system recorded a great variability of current-induced features, both longitudinal and transverse in different sub-environments dominated by gravel and sand to silty sand sediments: furrows, contouritic channels, terraces, and drift domains. The spatial distribution of the bedforms confirms the general westward decrease in energy of the MOW. But the bedform patterns reflect a great variability in the velocity and direction of the bottom current at local scale. This fact suggests a complex scenario characterized by the combination of different hydrodynamic processes action