the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Trace metal evidence for a poorly ventilated glacial Southern Ocean
M. Wagner
I. L. Hendy
Abstract. Glacial benthic δ13C and Δ14C measurements from the Atlantic Ocean have been interpreted to indicate the existence of a poorly ventilated Southern Ocean with greater CO2 and nutrient contents compared to present. Enhanced storage of CO2 in the deep ocean predicts that oxygen concentrations should have declined at the same time, although no unequivocal evidence for glacial Southern Ocean suboxia has yet been found. Here we take a novel approach by using concentrations of redox-sensitive trace metals to show that Southern Ocean sediments from two cores in the Atlantic sector were suboxic during deglaciation and the last glacial period, implying reduced ventilation and/or elevated export production that significantly altered deep water chemistry. In the Cape Basin, high concentrations of the authigenically deposited trace metal Re coincide with oldest Δ14C values at 3.8 km water depth in the Subantarctic Zone, indicating that poorest Southern Ocean ventilation occurred during the Last Glacial Maximum (~ 23–19 ka). Furthermore, trace metal results suggest that the vertical structure of the glacial Southern Ocean differed from modern deep water mass arrangement such that Lower Circumpolar Deep Water had lower O2 concentrations, and therefore was the likely reservoir of glacial CO2.
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M. Wagner and I. L. Hendy


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RC C225: 'comments on MS cp-2014-148', Anonymous Referee #1, 14 Apr 2015
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AC C827: 'Author response to Referee #1', Meghan Wagner, 26 Jun 2015
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AC C827: 'Author response to Referee #1', Meghan Wagner, 26 Jun 2015
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RC C430: 'Review 2', Anonymous Referee #2, 20 May 2015
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AC C842: 'Author response to Referee #2', Meghan Wagner, 26 Jun 2015
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AC C842: 'Author response to Referee #2', Meghan Wagner, 26 Jun 2015


-
RC C225: 'comments on MS cp-2014-148', Anonymous Referee #1, 14 Apr 2015
-
AC C827: 'Author response to Referee #1', Meghan Wagner, 26 Jun 2015
-
AC C827: 'Author response to Referee #1', Meghan Wagner, 26 Jun 2015
-
RC C430: 'Review 2', Anonymous Referee #2, 20 May 2015
-
AC C842: 'Author response to Referee #2', Meghan Wagner, 26 Jun 2015
-
AC C842: 'Author response to Referee #2', Meghan Wagner, 26 Jun 2015
M. Wagner and I. L. Hendy
M. Wagner and I. L. Hendy
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Cited
2 citations as recorded by crossref.
- Coupled climate–carbon cycle simulation of the Last Glacial Maximum atmospheric CO<sub>2</sub> decrease using a large ensemble of modern plausible parameter sets K. Kemppinen et al. 10.5194/cp-15-1039-2019
- Covariation of deep Southern Ocean oxygenation and atmospheric CO2 through the last ice age S. Jaccard et al. 10.1038/nature16514