1. Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years
- Author
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Weber, M.E., Bailey, I., Hemming, S.R., Martos, Y.M., Reilly, B.T., Ronge, T.A., Brachfeld, S., Williams, T., Raymo, M., Belt, M., Smik, L., vogel, H., Peck, V., Armbrecht, L., Cage, A., Cardillo, F.G., Du, Z., Fauth, G., Fogwill, C.J., and García-García, M. (Margarita)
- Subjects
carbon ,carbon cycle ,pleistocene ,Medio Marino ,Centro Oceanográfico de Cádiz ,ice ages ,antarctic zone - Abstract
The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust deposition became more pronounced across the Mid-Pleistocene Transition (MPT) in the Southern Hemisphere, with an abrupt shift suggesting more severe glaciations since ~0.9 Ma. Productivity was intermediate pre-MPT, lowest during the MPT and highest since 0.4 Ma. Generally, glacials experienced extended sea-ice cover, reduced bottom-water export and Weddell Gyre dynamics, which helped lower atmospheric CO2 levels., SI
- Published
- 2022