Recent morpho-sedimentary processes in Dove Basin, southern Scotia Sea, Antarctica: A basin-scale case of interaction between bottom currents and mass movements

• Published in: Marine Geology
• Main Authors: Lobo, F.J., López-Quirós, A., Hernández-Molina, F.J., Pérez, L., García, L.F., Evangelinos, D., Bohoyo, F., Rodríguez-Fernández, J., Salabarnada, A., Maldonado, A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Antarctic; Weddell Sea; Scotia Sea; Weddell; Central Basin; Antarc*; Antarctica
• Online Access: http://nora.nerc.ac.uk/id/eprint/529603/; https://nora.nerc.ac.uk/id/eprint/529603/1/1-s2.0-S0025322721001808-main.pdf; https://www.sciencedirect.com/science/article/pii/S0025322721001808

Multibeam bathymetric imagery and acoustic sub-bottom profiles are used to reveal distribution patterns of sub-surface sedimentation in Dove Basin (Scotia Sea). The goals of the study are to determine the imprint of the inflow of deep Antarctic water masses from the Weddell Sea into the Scotia Sea, to establish the factors driving the styles of contourite deposition and to discern the relative contribution of alongslope versus downslope processes to the construction of the uppermost late Quaternary sedimentary record in the basin. The most significant morpho-sedimentary features in Dove Basin are linked to contouritic processes and to mass movements. Plastered drifts on the flanks of the basin constitute the most common contouritic deposits. Basement-controlled drifts on top of structural elevations are common along the central ridge, the central basin plain and scattered along the basin flanks. Sheeted drifts occur on top of adjacent banks or are restricted to the deep basin. In contrast, mounded drifts are poorly represented in Dove basin. A laterally extensive contouritic channel runs along the central ridge. Contouritic channels are also identified in the upper parts of the lateral banks and slopes. Numerous slide scars along the upper parts of the slopes evolve downslope into semitransparent lens-shaped bodies, with occasional development of across-slope channels. Semitransparent lenses occur intercalated within stratified deposits in the slopes of the basin, in the central ridge and in the deepest basin plain. The spatial arrangement of contouritic morphologies points to the influence of the water column structure and the basin physiography. In the eastern sub-basin, two different fractions (lower and upper) of Weddell Sea Deep Water (WSDW) leave an imprint on contourite deposits owing to the sloping interface between the two fractions. Contouritic influence is more subdued in the western sub-basin, and limited to the imprint of the lower WSDW. The upper parts of the surrounding banks are under the ...