Large-and medium-scale morphosedimentary features of the Messina Strait. Insights into bottom-current-controlled sedimentation and interaction with downslope processes

The Messina Strait is a ~ 3-8 km wide and 40 km-long extensional area that connects the Tyrrhenian Sea with the Ionian Sea (Mediterranean Sea), and where tectonics, oceanographic and erosive-depositional downslope processes strongly interact each other. Based on the analysis of high-resolution multibeam data, we present an updated morpho-sedimentary framework that reveals a complex seabed morphology, characterized by a variety of features linked to bottom-currents and downslope processes. In particular, we recognize a suite of large to medium-scale erosive and depositional features, related to different bottom-currents (e.g., reverse tidal flows, residual flows, internal waves) acting over diverse time periods. Large scale bottom-current features are represented by contourite drifts and channels developed over long periods (> thousands of years). Medium-scale features formed during shorter time periods and include scours, furrows, transverse ridges (pinnacles) and narrow longitudinal bodies in the sill sector, along with several sand wave fields, located at greater depths on the Ionian and Tyrrhenian sides of the Messina Strait. Downslope processes encompass channelized features originated by sedimentary gravity flows, coarse-grained aprons and fans and submarine landslides. They mostly occur along strait margins and become predominant in the southern exit where the axial Messina canyon and its tributaries are present. Overall, our study shows that the MS is a fruitful area in which to investigate the interaction between recent erosive-depositional sedimentary and oceanographic processes, also modulated by sea-level fluctuations, during the last eustatic cycle. Moreover, the observed seabed morphologies and the associated processes provide insights for interpreting similar features in modern and ancient similar straits and seaways.