Deep-Sea Temperature and Circulation Changes at the Paleocene-Eocene Thermal Maximum
Abstract
A rapid increase in greenhouse gas levels is thought to have fueled global warming at the Paleocene-Eocene Thermal Maximum (PETM). Foraminiferal magnesium/calcium ratios indicate that bottom waters warmed by 4° to 5°C, similar to tropical and subtropical surface ocean waters, implying no amplification of warming in high-latitude regions of deep-water formation under ice-free conditions. Intermediate waters warmed before the carbon isotope excursion, in association with downwelling in the North Pacific and reduced Southern Ocean convection, supporting changing circulation as the trigger for methane hydrate release. A switch to deep convection in the North Pacific at the PETM onset could have amplified and sustained warming.
Get full access to this article
View all available purchase options and get full access to this article.
Already a Subscriber?Sign In
Supplementary Material
File (tripati-som.pdf)
References and Notes
1
J. P. Kennett, L. D. Stott, Nature353, 225 (1991).
2
E. Thomas, N. J. Shackleton, in Correlation of the Early Paleogene in Northwest Europe, R. W. O. Knox, R. M. Corfield, R. E. Dunay, Eds. (Geological Society Special Publication 101, London, 1996), pp. 401–441.
3
P. L. Koch, J. C. Zachos, P. D. Gingerich, Nature358, 319 (1992).
4
G. R. Dickens, J. R. O'Neil, D. C. Rea, R. M. Owen, Paleoceanography10, 965 (1995).
5
G. R. Dickens, M. M. Castillo, J. C. G. Walker, Geology25, 259 (1997).
6
G. A. Schmidt, D. T. Shindell, Paleoceanography18,2003).
7
A. Tripati, H. Elderfield, Geochem. Geophys. Geosyst.5,2004).
8
J. Zachos et al., Science302, 1551 (2003).
9
We analyzed Oridorsalis umbonatus, Nuttallides truempyi, and Cibicidoides spp. benthic taxa that have previously been used to reconstruct low-resolution TB records for the Cenozoic and high-resolution records across the Eocene-Oligocene boundary (11). Seawater Mg/Ca can be considered constant over the duration of the PETM, because of the relatively long oceanic residence times of Ca (∼106 years) and Mg (107 years) (29). The magnitude of warming calculated is therefore independent of seawater Mg/Ca ratio used. Absolute temperatures were calculated with current estimates for taxon-specific pre-exponential constants (30) and reconstructions of seawater Mg/Ca for 55 Ma (3.1 mmol/mol) (31).
10
Materials and methods are available as supporting material on Science Online.
11
C. Lear, H. Elderfield, P. Wilson, Science287, 269 (2000).
12
Shipboard Scientific Party, “Arctic Coring Expedition (ACEX): Paleoceanographic and tectonic evolution of the central Arctic Ocean” (Integrated Ocean Drilling Program Preliminary Report 302, ECORD, 2005), available at www.ecord.org/exp/acex/302PR.html.
13
D. K. Pak, K. G. Miller, Paleoceanography7, 405 (1992).
14
R. Corfield, J. Cartlidge, Terra Nova4, 443 (1992).
15
K. Miller, R. Fairbanks, G. Mountain, Paleoceanography2, 1 (1987).
16
K. L. Bice, J. Marotzke, Paleoceanography17, 9 (2002).
17
H. Stoll, S. Bains, Paleoceanography18,2003).
18
D. J. Thomas, T. J. Bralower, C. E. Jones, Earth Planet. Sci. Lett.209, 309 (2003).
19
D. J. Thomas, J. C. Zachos, T. J. Bralower, E. Thomas, S. Bohaty, Geology30, 1067 (2002).
20
R. W. Knox, in Late Paleocene-Early Eocene Climatic and Biotic Events in the Marine and Terrestrial Record, M. P. Aubry, S. G. Lucas, W. A. Berggren, Eds. (Columbia Univ. Press, New York, 1998), pp. 91–102.
21
H. Rennsen, C. J. Beefs, T. Fichefet, H. Goosse, D. Kroon, Paleoceanography19,2004).
22
A. Inamdar, V. Ramanathan, J. Geophys. Res.103, 32177 (1998).
23
C. Robert, J. P. Kennett, Geology22, 211 (1994).
24
G. J. Bowen, D. J. Beerling, P. L. Koch, J. C. Zachos, T. Quattlebaum, Nature432, 495 (2004).
25
S. Manabe, R. T. Wetherald, J. Atmos. Sci.24, 241 (1967).
26
D. Rind et al., Nature349, 500 (1991).
27
D. J. Beerling, Palaeogeogr. Palaeoclimatol. Palaeoecol.161, 395 (2000).
28
G. Ravizza, R. N. Norris, J. Blusztajn, M. P. Aubry, Paleoceanography16, 155 (2001).
29
W. S. Broecker, T. H. Peng, Tracers in the Sea (Eldigio, Palisades, NY, 1982).
30
C. Lear, Y. Rosenthal, N. Slowey, Geochim. Cosmochim. Acta66, 3375 (2002).
31
B. Wilkinson, T. Algeo, Am. J. Sci.289, 1158 (1989).
32
We thank W. Broecker for discussions; K. Bice, M. Bickle, S. Crowhurst, and A. Piotrowski for thoughtful reviews; R. Eagle for his support and advice; P. Rumford, B. Horan, and Gulf Coast Ocean Drilling Program Repository staff for provision of samples; and L. Booth, P. Ferretti, and M. Greaves for their invaluable technical help. This research used samples and data provided by the Ocean Drilling Program (ODP). Supported by the Comer Foundation.
Information & Authors
Information
Published In
Science
Volume 308 | Issue 5730
24 June 2005
24 June 2005
Copyright
American Association for the Advancement of Science.
Submission history
Received: 27 December 2004
Accepted: 20 May 2005
Published in print: 24 June 2005
Authors
Metrics & Citations
Metrics
Article Usage
Altmetrics
Citations
Export citation
Select the format you want to export the citation of this publication.
Cited by
- Lithium isotope evidence for enhanced weathering and erosion during the Paleocene-Eocene Thermal Maximum, Science Advances, 7, 42, (2021)./doi/10.1126/sciadv.abh4224
Loading...
View Options
Get Access
Log in to view the full text
AAAS login provides access to Science for AAAS Members, and access to other journals in the Science family to users who have purchased individual subscriptions.
- Become a AAAS Member
- Activate your AAAS ID
- Purchase Access to Other Journals in the Science Family
- Account Help
Log in via OpenAthens.
Log in via Shibboleth.
More options
Purchase digital access to this article
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
View options
PDF format
Download this article as a PDF file
Download PDF