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.

Science 7 April 2006:
Vol. 312. no. 5770, pp. 79 - 83
DOI: 10.1126/science.1120395
Prev | Table of Contents | Next

Research Articles

Evolution of the Eastern Tropical Pacific Through Plio-Pleistocene Glaciation

Kira T. Lawrence,* Zhonghui Liu, Timothy D. Herbert

A tropical Pacific climate state resembling that of a permanent El Niño is hypothesized to have ended as a result of a reorganization of the ocean heat budget ~3 million years ago, a time when large ice sheets appeared in the high latitudes of the Northern Hemisphere. We report a high-resolution alkenone reconstruction of conditions in the heart of the eastern equatorial Pacific (EEP) cold tongue that reflects the combined influences of changes in the equatorial thermocline, the properties of the thermocline's source waters, atmospheric greenhouse gas content, and orbital variations on sea surface temperature (SST) and biological productivity over the past 5 million years. Our data indicate that the intensification of Northern Hemisphere glaciation ~3 million years ago did not interrupt an almost monotonic cooling of the EEP during the Plio-Pleistocene. SST and productivity in the eastern tropical Pacific varied in phase with global ice volume changes at a dominant 41,000-year (obliquity) frequency throughout this time. Changes in the Southern Hemisphere most likely modulated most of the changes observed.

Department of Geological Sciences, Brown University, Box 1846, Providence, RI 02912, USA.

* To whom correspondence should be addressed. E-mail: kira_lawrence{at}brown.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Radiation of Extant Cetaceans Driven by Restructuring of the Oceans.
M. E. Steeman, M. B. Hebsgaard, R. E. Fordyce, S. Y. W. Ho, D. L. Rabosky, R. Nielsen, C. Rahbek, H. Glenner, M. V. Sorensen, and E. Willerslev (2009)
Syst Biol 58, 573-585
   Abstract »    Full Text »    PDF »
Pliocene-Pleistocene variability of upwelling activity, productivity, and nutrient cycling in the Benguela region.
J. Etourneau, P. Martinez, T. Blanz, and R. Schneider (2009)
Geology 37, 871-874
   Abstract »    Full Text »    PDF »
Deep-Sea Temperature and Ice Volume Changes Across the Pliocene-Pleistocene Climate Transitions.
S. Sosdian and Y. Rosenthal (2009)
Science 325, 306-310
   Abstract »    Full Text »    PDF »
Pacific elements in the Caribbean Neogene gastropod fauna: the source-sink model, larval development, disappearance, and faunal units.
B. Landau, C. Marques Da Silva, and G. Vermeij (2009)
Bulletin de la Societe Geologique de France 180, 343-352
   Abstract »    Full Text »    PDF »
Atmospheric Carbon Dioxide Concentration Across the Mid-Pleistocene Transition.
B. Honisch, N. G. Hemming, D. Archer, M. Siddall, and J. F. McManus (2009)
Science 324, 1551-1554
   Abstract »    Full Text »    PDF »
Greatly Expanded Tropical Warm Pool and Weakened Hadley Circulation in the Early Pliocene.
C. M. Brierley, A. V. Fedorov, Z. Liu, T. D. Herbert, K. T. Lawrence, and J. P. LaRiviere (2009)
Science 323, 1714-1718
   Abstract »    Full Text »    PDF »
Climate control on Quaternary coal fires and landscape evolution, Powder River basin, Wyoming and Montana.
C. A. Riihimaki, P. W. Reiners, and E. L. Heffern (2009)
Geology 37, 255-258
   Abstract »    Full Text »    PDF »
Introduction. Pliocene climate, processes and problems.
A. M Haywood, H. J Dowsett, P. J Valdes, D. J Lunt, J. E Francis, and B. W Sellwood (2009)
Phil Trans R Soc A 367, 3-17
   Abstract »    Full Text »    PDF »
The Arctic cryosphere in the Mid-Pliocene and the future.
D. J Lunt, A. M Haywood, G. L Foster, and E. J Stone (2009)
Phil Trans R Soc A 367, 49-67
   Abstract »    Full Text »    PDF »
Dispersal and biogeography of marine plankton: Long-distance dispersal of the foraminifer Truncorotalia truncatulinoides.
P. F. Sexton and R. D. Norris (2008)
Geology 36, 899-902
   Abstract »    Full Text »    PDF »
Early Pliocene (pre Ice Age) El Nino like global climate: Which El Nino?.
P. Molnar and M. A. Cane (2007)
Geosphere 3, 337-365
   Abstract »    Full Text »    PDF »
Impacts of the North Atlantic gyre circulation on Holocene climate off northwest Africa.
J.-H. Kim, H. Meggers, N. Rimbu, G. Lohmann, T. Freudenthal, P. J. Muller, and R. R. Schneider (2007)
Geology 35, 387-390
   Abstract »    Full Text »    PDF »
The Pliocene paradox (mechanisms for a permanent El Nino)..
A. V. Fedorov, P. S. Dekens, M. McCarthy, A. C. Ravelo, P. B. deMenocal, M. Barreiro, R. C. Pacanowski, and S. G. Philander (2006)
Science 312, 1485-1489
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

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