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


Weber, ME and Bailey, I and Hemming, SR and Martos, YM and Reilly, BT and Ronge, TA and Brachfeld, S and Williams, T and Raymo, M and Belt, ST and Smik, L and Vogel, H and Peck, VL and Armbrecht, L and Cage, A and Cardillo, FG and Du, Z and Fauth, G and Fogwill, CJ and Garcia, M and Garnsworthy, M and Gluder, A and Guitard, M and Gutjahr, M and Hernandez-Almeida, I and Hoem, FS and Hwang, JH and Iizuka, M and Kato, Y and Kenlee, B and OConnell, S and Perez, LF and Seki, O and Stevens, L and Tauxe, L and Tripathi, S and Warnock, J and Zheng, X, Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years, Nature Communications, 13, (1) Article 2044. ISSN 2041-1723 (2022) [Refereed Article]

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DOI: doi:10.1038/s41467-022-29642-5


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.

Item Details

Item Type:Refereed Article
Keywords:Antarctica, productivity, dust, Southern Ocean, Mid-Pleistocene Transition, diatoms, silica
Research Division:Earth Sciences
Research Group:Physical geography and environmental geoscience
Research Field:Palaeoclimatology
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Antarctic and Southern Ocean oceanic processes
UTAS Author:Armbrecht, L (Dr Linda Armbrecht)
ID Code:150407
Year Published:2022
Web of Science® Times Cited:2
Deposited By:Ecology and Biodiversity
Deposited On:2022-06-13
Last Modified:2022-06-15

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