Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years

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, c...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Weber, ME, Bailey, I, Hemming, SR, Martos, YM, Reilly, BT, Ronge, TA, Brachfeld, S, Williams, T, Raymo, M, Belt, ST, Smik, L, Vogel, H, Peck, VL, Armbrecht, L, Cage, A, Cardillo, FG, Du, Z, Fauth, G, Fogwill, CJ, Garcia, M, Garnsworthy, M, Gluder, A, Guitard, M, Gutjahr, M, Hernandez-Almeida, I, Hoem, FS, Hwang, JH, Iizuka, M, Kato, Y, Kenlee, B, OConnell, S, Perez, LF, Seki, O, Stevens, L, Tauxe, L, Tripathi, S, Warnock, J, Zheng, X
Format: Article in Journal/Newspaper
Language:English
Published: Nature Publishing Group 2022
Subjects:
Earth Sciences
Physical geography and environmental geoscience
Palaeoclimatology
Antarctic
Patagonia
Southern Ocean
The Antarctic
Weddell
Antarc*
Sea ice
Online Access:https://doi.org/10.1038/s41467-022-29642-5
http://www.ncbi.nlm.nih.gov/pubmed/35440628
http://ecite.utas.edu.au/150407
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Summary: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 CO 2 levels.

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