TY - JOUR
T1 - Geomorphology of Ona Basin, southwestern Scotia Sea (Antarctica)
T2 - Decoding the spatial variability of bottom-current pathways
AU - López-Quirós, Adrián
AU - Lobo, Francisco J.
AU - Escutia, Carlota
AU - García, Marga
AU - Hernández-Molina, F. Javier
AU - Pérez, Lara F.
AU - Bohoyo, Fernando
AU - Evangelinos, Dimitris
AU - Salabarnada, Ariadna
AU - Maldonado, Andrés
AU - Naveira Garabato, Alberto C.
N1 - Funding Information:
Funding for this research was provided by the Spanish Ministry of Science and Innovation (grants CTM2014-60451-C2-1/2-P , CTM2017-89711-C2-1/2-P , and CGL2015-74216-JIN ) co-financed by the European Regional Development Fund (FEDER). The corresponding author acknowledges an FPI fellowship of the Spanish Ministry of Science and Innovation. We thank the Commander, officers, crew, and scientific staff of the BIO HESPERIDES for their support in obtaining the data, sometimes under severe sea conditions. We would also like to thank Editor Dr. Michele Rebesco and two anonymous referees for their constructive suggestions to improve the paper. We thank Jean Sanders for correction of the English text. Seismic interpretations were made using Kingdom Suite™ software, thanks to the participation of the Instituto Andaluz de Ciencias de la Tierra in the IHS University Grant program.
Funding Information:
Funding for this research was provided by the Spanish Ministry of Science and Innovation (grants CTM2014-60451-C2-1/2-P, CTM2017-89711-C2-1/2-P, and CGL2015-74216-JIN) co-financed by the European Regional Development Fund (FEDER). The corresponding author acknowledges an FPI fellowship of the Spanish Ministry of Science and Innovation. We thank the Commander, officers, crew, and scientific staff of the BIO HESPERIDES for their support in obtaining the data, sometimes under severe sea conditions. We would also like to thank Editor Dr. Michele Rebesco and two anonymous referees for their constructive suggestions to improve the paper. We thank Jean Sanders for correction of the English text. Seismic interpretations were made using Kingdom Suite? software, thanks to the participation of the Instituto Andaluz de Ciencias de la Tierra in the IHS University Grant program.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/4
Y1 - 2020/4
N2 - Ona Basin, the westernmost oceanic basin in the southern Scotia Sea, is affected by the opposite flows of Circumpolar Deep Water (CDW) and Weddell Sea Deep Water (WSDW); thus, it represents a key location for exploring seafloor morphologies influenced by bottom currents. The present study aims to capture the spatial arrangement of recent subsurface contourite features, assuming a latitudinal influence of water masses and the interactions between along- and downslope processes, in order to contribute to the knowledge of regional deepwater flow pathways and to the sedimentary model of small sediment-starved oceanic basins. To this end, the investigation combines an interpretation of multibeam bathymetry and parametric echo sounder seismic data complemented with hydrological data. The distribution of morpho-sedimentary features in Ona Basin reveals two major domains. The southern margin of the basin can be regarded as a mixed/hybrid system containing abundant sediment drifts with channels and contourite moats and a lateral continuity interrupted by downslope morphologies. In contrast, the northern abyssal setting comprises relatively homogeneous large sheeted drifts with superimposed sediment waves, mounded drifts, and several scattered erosive features, likely reflecting the more distinct influence of deepwater contourite processes. Our work demonstrates that tectonic features in the southern basin control the interaction between deepwater along- and downslope processes, as the westward flow of the WSDW is deflected, channelized, and intensified along its westward route. In the northern region, the study indicates an overall clockwise rotation of the WSDW flow, with the spatial and vertical variability of CDW and WSDW affecting the distribution of bottom-current features around seamounts and/or structural highs. The results underscore the importance of sloping interphases in the water mass vertical structure, the degree of basin confinement, and the influence of local bathymetric elevations in sedimentation models of small sediment-starved oceanic basins.
AB - Ona Basin, the westernmost oceanic basin in the southern Scotia Sea, is affected by the opposite flows of Circumpolar Deep Water (CDW) and Weddell Sea Deep Water (WSDW); thus, it represents a key location for exploring seafloor morphologies influenced by bottom currents. The present study aims to capture the spatial arrangement of recent subsurface contourite features, assuming a latitudinal influence of water masses and the interactions between along- and downslope processes, in order to contribute to the knowledge of regional deepwater flow pathways and to the sedimentary model of small sediment-starved oceanic basins. To this end, the investigation combines an interpretation of multibeam bathymetry and parametric echo sounder seismic data complemented with hydrological data. The distribution of morpho-sedimentary features in Ona Basin reveals two major domains. The southern margin of the basin can be regarded as a mixed/hybrid system containing abundant sediment drifts with channels and contourite moats and a lateral continuity interrupted by downslope morphologies. In contrast, the northern abyssal setting comprises relatively homogeneous large sheeted drifts with superimposed sediment waves, mounded drifts, and several scattered erosive features, likely reflecting the more distinct influence of deepwater contourite processes. Our work demonstrates that tectonic features in the southern basin control the interaction between deepwater along- and downslope processes, as the westward flow of the WSDW is deflected, channelized, and intensified along its westward route. In the northern region, the study indicates an overall clockwise rotation of the WSDW flow, with the spatial and vertical variability of CDW and WSDW affecting the distribution of bottom-current features around seamounts and/or structural highs. The results underscore the importance of sloping interphases in the water mass vertical structure, the degree of basin confinement, and the influence of local bathymetric elevations in sedimentation models of small sediment-starved oceanic basins.
KW - Bottom-current circulation
KW - Contourites
KW - Mass movements
KW - Ona Basin
KW - Scotia Sea
KW - Seafloor morphology
UR - http://www.scopus.com/inward/record.url?scp=85078548773&partnerID=8YFLogxK
U2 - 10.1016/j.margeo.2020.106113
DO - 10.1016/j.margeo.2020.106113
M3 - Article
AN - SCOPUS:85078548773
SN - 0025-3227
VL - 422
JO - Marine Geology
JF - Marine Geology
M1 - 106113
ER -