Bedforms of Bonifacio Strait (Western Mediterranean): hydrodynamics, coastal outline, supply and sediment distribution

Abstract

Abstract This paper shows the results of high-resolution survey on the continental shelf of Bonifacio Strait (north Sardinia). Multisensor and multiscale data obtained by means of sub-bottom profiler CHIRP and multibeam and side-scan sonar made it possible to identify the morphological features of bedforms. The analysis of both side-scan sonar sonograms mosaic and high-resolution seismic data allowed us to perform a detailed mapping of various substrates highlighting the presence of complex bedform associations. These bedform associations are typical of continental shelf environments affected by high-speed bottom currents. Multisource data analysis integrated by sedimentological study allowed us to identify the directions of sediment movements on the seabed and the progradation of bedforms. Locally, it was found that the bedforms of mobile bottoms are still active and they persist for more than a decade. The path of the currents’ circulation revealed that in the Bonifacio Strait, the bottom currents flow westwards, opposed to the prevailing sea surface flows.