Morphology and sedimentary processes in Santa Catarina Plateau and Vema Channel, Brazil

This paper investigates the deep-sea morphology and sedimentary processes within the Santa Catarina Plateau and the Vema Channel, prominent features crucial for influencing bottom circulation in the western South Atlantic and regulating the exchange of deep and bottom waters between the Argentine and Brazil basins. The study leverages a unique dataset comprising multibeam data for generating detailed digital terrain models and sub-bottom profiling records, alongside numerical modeling of bottom current velocities (GLORYS12V1 reanalysis). Numerous sediment waves, predominantly cresting mudwaves and mass-wasting deposits associated with steeper sea floor gradients, were identified in the region, aligning with findings from the Argentinian and South Brazilian slopes. The investigation of these features contributes not only to the identification of contourites but also to the enhancement of understanding regarding deep-water circulation within the 3,500-to-4,500-meter range. This depth range serves as a critical transition zone between the Argentine and Brazil basins and plays a pivotal role in elucidating the northward distribution of Antarctic Bottom Water (AABW), an integral component of the Atlantic meridional circulation. In contrast to prior studies that focused on specific regions of the plateau, this research offers a comprehensive overview of the region's morphology and sedimentary processes, thereby advancing comprehension of deep-water circulation dynamics between the Argentinian and Brazilian basins.