Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Focus on Europe

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 17 September 2004:
Vol. 305. no. 5691, pp. 1766 - 1770
DOI: 10.1126/science.1100061
Prev | Table of Contents | Next

Reports

Middle Miocene Southern Ocean Cooling and Antarctic Cryosphere Expansion

Amelia E. Shevenell,* James P. Kennett, David W. Lea

Magnesium/calcium data from Southern Ocean planktonic foraminifera demonstrate that high-latitude (~55°S) southwest Pacific sea surface temperatures (SSTs) cooled 6° to 7°C during the middle Miocene climate transition (14.2 to 13.8 million years ago). Stepwise surface cooling is paced by eccentricity forcing and precedes Antarctic cryosphere expansion by ~60 thousand years, suggesting the involvement of additional feedbacks during this interval of inferred low-atmospheric partial pressure of CO2 (pCO2). Comparing SSTs and global carbon cycling proxies challenges the notion that episodic pCO2 drawdown drove this major Cenozoic climate transition. SST, salinity, and ice-volume trends suggest instead that orbitally paced ocean circulation changes altered meridional heat/vapor transport, triggering ice growth and global cooling.

Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, CA 93106–9630, USA

* To whom correspondence should be addressed. E-mail: ashevenell{at}umail.ucsb.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Adaptive Evolution of Hepcidin Genes in Antarctic Notothenioid Fishes.
Q. Xu, C.-H. C. Cheng, P. Hu, H. Ye, Z. Chen, L. Cao, L. Chen, Y. Shen, and L. Chen (2008)
Mol. Biol. Evol. 25, 1099-1112
   Abstract »    Full Text »    PDF »
Mammalian Communities Document a Latitudinal Environmental Gradient during the Miocene Climatic Optimum in Western Europe.
L. Costeur and S. Legendre (2008)
Palaios 23, 280-288
   Abstract »    Full Text »    PDF »
Integrated stratigraphy and palaeoecology of the Lower and Middle Miocene of the Porcupine Basin.
S. LOUWYE, A. FOUBERT, K. MERTENS, D. VAN ROOIJ, and THE IODP EXPEDITION 307 SCIENTIFIC PARTY (2008)
Geological Magazine 145, 321-344
   Abstract »    Full Text »    PDF »
Genome structure and emerging evidence of an incipient sex chromosome in Populus.
T. Yin, S. P. DiFazio, L. E. Gunter, X. Zhang, M. M. Sewell, S. A. Woolbright, G. J. Allan, C. T. Kelleher, C. J. Douglas, M. Wang, et al. (2008)
Genome Res. 18, 422-430
   Abstract »    Full Text »    PDF »
From the Cover: The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems.
W. M. Kurschner, Z. Kvacek, and D. L. Dilcher (2008)
PNAS 105, 449-453
   Abstract »    Full Text »    PDF »
Brachiopods in Epeiric Seas as Monitors of Secular Changes in Ocean Chemistry: A Miocene Example from the Murray Basin, South Australia.
P. K. Pufahl, N. P. James, T. K. Kyser, J. J. Lukasik, and Y. Bone (2006)
Journal of Sedimentary Research 76, 926-941
   Abstract »    Full Text »    PDF »
Stable isotope paleoaltimetry: A critical review.
P. M. Blisniuk and L. A. Stern (2005)
Am J Sci 305, 1033-1074
   Abstract »    Full Text »    PDF »


ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)