Iron Fertilization of the Subantarctic Ocean During the Last Ice Age

Martinez-Garcia, A.; Sigman, D. M.; Ren, H.; Anderson, R. F.; Straub, M.; Hodell, D. A.; Jaccard, Samuel; Eglinton, T. I.; Haug, G. H. (2014). Iron Fertilization of the Subantarctic Ocean During the Last Ice Age. Science, 343(6177), pp. 1347-1350. American Association for the Advancement of Science 10.1126/science.1246848

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John H. Martin, who discovered widespread iron limitation of ocean productivity, proposed that dust-borne iron fertilization of Southern Ocean phytoplankton caused the ice age reduction in atmospheric carbon dioxide (CO2). In a sediment core from the Subantarctic Atlantic, we measured foraminifera-bound nitrogen isotopes to reconstruct ice age nitrate consumption, burial fluxes of iron, and proxies for productivity. Peak glacial times and millennial cold events are characterized by increases in dust flux, productivity, and the degree of nitrate consumption; this combination is uniquely consistent with Subantarctic iron fertilization. The associated strengthening of the Southern Ocean’s biological pump can explain the lowering of CO2 at the transition from mid-climate states to full ice age conditions as well as the millennial-scale CO2 oscillations.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Jaccard, Samuel

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0036-8075

Publisher:

American Association for the Advancement of Science

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

02 Oct 2014 10:36

Last Modified:

19 Oct 2015 09:40

Publisher DOI:

10.1126/science.1246848

BORIS DOI:

10.7892/boris.57917

URI:

https://boris.unibe.ch/id/eprint/57917

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