Abstract
THE biological productivity of the oceans is sensitive to changes in climate, which can affect essential factors such as nutrient and light availability. In turn, ocean productivity may influence climate by regulating the partitioning of carbon dioxide, a greenhouse gas, between the ocean and the atmosphere. Investigators have attempted to link variations in atmospheric CO2 content, recorded in ice cores1,2, to the productivity of the Southern Ocean3–6, but an unambiguous means of assessing past changes in ocean productivity has been lacking. Here we exploit established relationships between 231Pa/230Th ratios and particle flux7–12 to infer, from the analysis of dated sediment cores, variability through time of fluxes of particulate biogenic material exported from surface waters. Records from two cores in the Atlantic sector of the Southern Ocean indicate that ocean productivity during glacial periods was lower than at present south of the Antarctic polar front, and support earlier conclusions13–16 that the zone of maximum productivity migrated northwards during glacial conditions. Although further work at other sites is needed for an assessment of changes in total Antarctic productivity, our technique has the potential to provide this information while avoiding some of the limitations of other productivity proxies.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Barnola, J. M., Raynaud, D., Korotkevich, Y. S. & Lorius, C. Nature 329, 408–413 (1987).
Neftel, A., Oeschger, H., Staffelbach, T. & Stauffer, B. Nature 331, 609–611 (1988).
Knox, F. & McElroy, M. B. J. geophys. Res. 89, 4629–4637 (1984).
Sarmiento, J. L. & Toggweiler, J. R. Nature 308, 621–624 (1984).
Kier, R. S. Paleoceanography 5, 253–276 (1990).
Martin, J. H. Paleoceanography 5, 1–13 (1990).
Anderson, R. F., Bacon, M. P. & Brewer, P. G. Earth planet. Sci. Lett. 62, 7–23 (1983).
Anderson, R. F., Bacon, M. P. & Brewer, P. G. Earth planet. Sci. Lett. 66, 73–90 (1983).
Taguchi, K., Harada, K. & Tsunogai, S. Earth planet. Sci. Lett. 93, 223–232 (1989).
Lao, Y. et al. Earth planet. Sci. Lett. 113, 173–189 (1992).
Lao, Y., Anderson, R. F., Broecker, W. S., Hofmann, H. J. & Wolfli, W. Geochim. cosmochim. Acta 57, 205–217 (1993).
Yang, H. S., Nozaki, Y., Sakai, Y. & Masuda, A. Geochim. cosmochim. Acta 50, 81–89 (1986).
Mortlock, R. A. et al. Nature 351, 220–222 (1991).
Charles, C. D., Froelich, P. N., Zibello, M. A., Mortlock, R. A. & Morley, J. J. Paleoceanography 6, 697–728 (1991).
Cooke, D. W. & Hays, J. D. in Antarctic Geoscience (ed. Craddock, C.) 1017–1025 (Univ. of Wisconsin, Madison, 1982).
Burckle, L. H. & Cirilli, J. Micropaleontology 33, 82–86 (1987).
Labeyrie, L. & Duplessy, J. C. Paleogeogr. Paleoclimatol. Pateoecol. 50, 217–240 (1985).
Charles, C. D. & Fairbanks, R. G. in The Geologic History of the Polar Oceans: Arctic vs Antarctic (eds Bleil, U. & Thiede, J.) 519–538 (Kluwer, Dordrecht, 1990).
Boyle, E. A. J. geophys. Res. 93, 15701–15715 (1988).
Keigwin, L. D. & Boyle, E. A. Paleogeogr. Paleoclimatol. Paleoecol. 73, 85–106 (1989).
Froeiich, P. N., Mortlock, R. A. & Shemesh, A. Global biogeochem. Cycles 3, 79–88 (1989).
Froeiich, P. N. et al. Paleoceanography (in the press).
Pichon, J.-J. et al. Quat. Res. 37, 361–378 (1992).
Berger, W. H. Nature 351, 186–187 (1991).
Deuser, W. G., Ross, E. H. & Anderson, R. F. Deep-Sea Res. A28, 495–505 (1981).
Ku, T. L., Knauss, K. G. & Mathieu, G. G. Deep-Sea Res. 24, 1005–1017 (1977).
Chen, J. H., Edwards, R. L. & Wasserburg, G. J. Earth planet. Sci. Lett. 80, 241–251 (1986).
Cochran, J. K. in Uranium Series Disequilibria: Applications to Environmental Problems (eds Ivanovich, M. & Harmon, R. S.) 384–430 (Clarendon, London, 1982).
Moore, W. S. & Sackett, W. M. J. geophys. Res. 69, 5401–5405 (1964).
Bacon, M. P. Isotope Geosci. 2, 97–111 (1984).
Francois, R., Bacon, M. P. & Suman, D. O. Paleoceanography 5, 761–787 (1990).
Yang, Y. L., Elderfield, H. & Ivanovich, M. Paleoceanography 5, 789–809 (1990).
Bacon, M. P. Phil. Trans. R. Soc. A325, 147–160 (1988).
Sarnthein, M., Winn, K., Duplessy, J.-C. & Fontugne, M. R. Paleoceanography 3, 361–399 (1988).
Lyle, M. Nature 335, 529–532 (1988).
Pedersen, T. M., Nielsen, B. & Pickering, M. Paleoceanography 6, 637–677 (1992).
Martinson, D. G. et al. Quat. Res. 27, 1–29 (1987).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kumar, N., Gwiazda, R., Anderson, R. et al. 231Pa/230Th ratios in sediments as a proxy for past changes in Southern Ocean productivity. Nature 362, 45–48 (1993). https://doi.org/10.1038/362045a0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/362045a0
This article is cited by
-
Southern Ocean glacial conditions and their influence on deglacial events
Nature Reviews Earth & Environment (2023)
-
Genetic diversity and novel lineages in the cosmopolitan copepod Pleuromamma abdominalis in the Southeast Pacific
Scientific Reports (2020)
-
Silicon-isotope composition of diatoms as an indicator of past oceanic change
Nature (1998)
-
Contribution of Southern Ocean surface-water stratification to low atmospheric CO2 concentrations during the last glacial period
Nature (1997)
-
Similar rates of modern and last-glacial ocean thermohaline circulation inferred from radiochemical data
Nature (1996)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
