(Table 1) Age determination of sediment core MD02-2589, supplement to: Molyneux, Elizabeth G; Hall, Ian R; Zahn, Rainer; Diz, Paula (2007): Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka. Paleoceanography, 22(4), PA4209


Sortable silt mean grain sizes together with oxygen and carbon isotopic data produced on the benthic foraminiferal species Fontbotia wuellerstorfi are used to construct high-resolution records of near-bottom flow vigour and deep water ventilation at a core site MD02-2589 located at 2660 m water depth on the southern Agulhas Plateau. The results suggest that during glacial periods (marine oxygen isotope stages 2 and 6, MIS 2 and MIS 6, respectively), there was a persistent contribution of a well-ventilated water mass within the Atlantic to Indian oceanic gateway with a d13C signature similar to present-day Northern Component Water (NCW), e.g., North Atlantic Deep Water (NADW). The records of chemical ventilation and near-bottom flow vigor reflect changes in the advection of northern source waters and meridional variability in the location of the Antarctic Circumpolar Current and its associated fronts. We suggest that during Termination II (TII), changes in chemical ventilation are largely decoupled from near-bottom physical flow speeds. A mid-TII climate optimum is associated with a low-flow speed plateau concurrent with a period of increased ventilation shown in the benthic d13C of other Southern Ocean records but not in our benthic d13C of MD02-2589. The climate optimum is followed by a period of southern cooling around 128 ka coincident with a stronger influence of NCW to interglacial levels at around 124 ka. All proxy records show a near synchronous and rapid shift during the transition from MIS 5a-4 (73 ka). This large event is attributed to a rapid decrease in NADW influence and replacement over the Agulhas Plateau by southern source waters.

DOI https://doi.org/10.1594/PANGAEA.832863
Related Identifier https://doi.org/10.1029/2006PA001407
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.832863
Creator Molyneux, Elizabeth G; Hall, Ian R; Zahn, Rainer; Diz, Paula
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2007
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Dataset
Format text/tab-separated-values
Size 104 data points
Discipline Earth System Research
Spatial Coverage (25.222 LON, -41.434 LAT); Southern Ocean