Publication Date:
2014-03-22
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martinez-Garcia, Alfredo -- Sigman, Daniel M -- Ren, Haojia -- Anderson, Robert F -- Straub, Marietta -- Hodell, David A -- Jaccard, Samuel L -- Eglinton, Timothy I -- Haug, Gerald H -- New York, N.Y. -- Science. 2014 Mar 21;343(6177):1347-50. doi: 10.1126/science.1246848.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Geological Institute, ETH Zurich, 8092 Zurich, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24653031" target="_blank"〉PubMed〈/a〉
Keywords:
Antarctic Regions
;
Atlantic Ocean
;
Atmosphere
;
Biomass
;
*Carbon Dioxide/analysis
;
*Climate
;
Cold Temperature
;
Foraminifera/chemistry/metabolism
;
*Geologic Sediments/chemistry
;
*Ice Cover
;
*Iron/analysis
;
Nitrates/analysis/metabolism
;
Nitrogen Isotopes/analysis
;
Phytoplankton/growth & development/metabolism
;
Seawater/chemistry
;
Time
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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