Asynchronous terrestrial and marine signals of climate change during Heinrich events

Science

Volumn 306, Issue 5705, 2004, Pages 2236-2239

  Jennerjahn, Tim C ^a   Ittekkot, Venugopalan ^a   Arz, Helge W ^b   Behling, Hermann ^c   Pätzold, Jürgen ^c   Wefer, Gerold ^c  

^a LEIBNIZ CENTRE FOR TROPICAL MARINE RESEARCH ZMT   (Germany)

^b GFZ GERMAN RESEARCH CENTRE FOR GEOSCIENCES   (Germany)

^c Deutsche Forschungsgemeinschaft   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ECOLOGY; ECOSYSTEMS; HYDROLOGY; MARINE SIGNAL SYSTEMS; SEDIMENTATION;

BRAZILIAN CONTINENTAL MARGIN; CLIMATE DYNAMICS; MARINE SEDIMENT; TROPICAL ECOSYSTEMS;

CLIMATE CHANGE;

CLIMATE CHANGE; HEINRICH EVENT; HYDROLOGICAL CHANGE; TROPICAL REGION;

ARTICLE; BRAZIL; CLIMATE CHANGE; DYNAMICS; ECOLOGY; ECOSYSTEM; GEOGRAPHIC DISTRIBUTION; HYDROLOGY; MARINE ENVIRONMENT; PRIORITY JOURNAL; SEDIMENTOLOGY; TROPICS;

ATLANTIC OCEAN; BRAZIL; CARBON ISOTOPES; CLIMATE; ECOSYSTEM; FERNS; GEOLOGIC SEDIMENTS; NITROGEN ISOTOPES; PLANTS; POLLEN; RAIN; SEAWATER; SPORES; TIME; TREES; TROPICAL CLIMATE;

EID: 11144252272     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1102490     Document Type: Article

References (37)

1. M. Sarnthein et al., Eos 81, 625 (2000).
2. R. A. Kerr, Science 292, 660 (2001).
3. W. S. Broecker, S. Hemming, Science 294, 2308 (2001).
4. E. Bard, F. Rostek, C. Sonzogni, Nature 385, 707 (1997).
5. M. Stute et al., Science 269, 379 (1995).
6. I. Farrera et al., Clim. Dyn. 15, 823 (1999).
7. K. A. Hughen, T. I. Eglinton, L. Xu, M. Makou, Science 304, 1955 (2004); published online 20 May 2004 (10.1126/science.1092995).
8. R. S. Bradley, Paleoclimatology (Academic Press, San Diego, CA, ed. 2, 1991).
9. H. W. Arz, J. Pätzold, G. Wefer, Quat. Res. 50, 157 (1998).
10. H. Behling, H. W. Arz, J. Pätzold, G. Wefer, Quat. Sci. Rev. 19, 981 (1999).
11. 3 content (9). Fe and Ti are related to siliciclastic components and have been shown to vary directly with the terrigenous mineral fraction of sediments (25). In a similar way, an increased supply of river-borne materials caused by millennial-scale hydrological changes has been inferred from increased Fe and Ti abundances in sediment cores from the Cariaco Basin (26).
12. G. Fischer, Mar. Chem. 35, 581 (1991).
13. E. M. Galimov, The Biological Fractionation of Isotopes (Academic Press, San Diego, CA, 1985).
14. 15N reflects the degree of OM degradation in our cores is also supported by amino acid data. High proportions of the nonprotein amino acids β-alanine and γ-aminobutyric acid in the beginning of a Heinrich event, indicating a high degree of OM degradation (30), decrease gradually toward its end (31).
15. M.-P. Ledru, P. Mourguiart, G. Ceccantini, B. Turcq, A. Sifeddine, Geology 30, 275 (2002).
16. Because the shelf break is located at about 50-m water depth in the investigated area, sea level was below it at least during the most pronounced events correlated with H1 and H6 but probably throughout the entire period of marine isotope stages 2 to 4 (32, 33). Therefore, shelf erosion due to sea level change should have been unimportant throughout this period.
17. T. J. Crowley, Paleoceanography 14, 271 (1999).
18. G.-R. Walther et al., Nature 416, 389 (2002).
19. P. A. Baker et al., Nature 409, 698 (2001).
20. A. J. Broccoli, J. Clim. 13, 951 (2000).
21. G. H. Haug, K. A. Hughen, D. M. Sigman, L. C Peterson, U. Röhl, Science 293, 1304 (2001).
22. C. Rühlemann, S. Mulitza, P. J. Müller, G. Wefer, R. Zahn, Nature 402, 511 (1999).
23. H. W. Arz, J. Pätzold, G. Wefer, Earth Planet. Sci. Lett. 167, 105 (1999).
24. Alternatively, the moisture could originate from the south. If global wind systems became more zonal during cold phases as has been suggested (34), the boreal winter ITCZ should have shifted northward. In our case, this would imply a southern moisture source responsible for the increased precipitation during Heinrich events, which could have been provided from southeast trade winds and/or polar advections. Currently the high rainfall south of Recife is restricted to the coastal stretch. The orographic barrier of the Brazilian highlands prevents substantial transport of moisture to the north and to the west. Therefore and for reasons given in the text, a southern source of moisture is rather unlikely. The suggested southward migration of the ITCZ would also help to explain the time lag of about 1000 years between the pollen records of Lagoa do Caço and that of our marine core, despite the possible chronological uncertainties of site-to-site correlations. The southward displacement of the ITCZ has led to the observed patterns of sedimentation and vegetation development as described. The subsequent migration of the ITCZ to the northwest may then have led to a similar vegetation development about 1000 years later in the Lagoa do Caço region.
25. J. H. F. Jansen, S. J. Van der Gaast, B. Koster, A. Vaars, Mar. Geol. 151, 143 (1998).
26. L. C. Peterson, G. H. Haug, K. A. Hughen, U. Röhl, Science 290, 1947 (2000).
27. E. Wada, A. Hattori, Nitrogen in the Sea: Forms, Abundances, and Rate Processes (CRC Press, Boca Raton, FL, 1991).
28. M. A. Altabet, R. Francois, Global Biogeochem. Cycles 8, 103 (1994).
29. H. T. Barretto, C. P. Summerhayes J. Sediment. Petrol. 45, 822 (1975).
30. T. C. Jennerjahn, V. Ittekkot, Mar. Geol. 161, 129 (1999).
31. T. C. Jennerjahn et al., unpublished data.
32. J. Chappell, N. J. Shackleton, Nature 324, 137 (1986).
33. R. G. Fairbanks, Nature 342, 637 (1989).
34. S. W. Hosteller, A. C. Mix, Nature 399, 673 (1999).
35. L. Vidal et al., Earth Planet. Sci. Lett. 146, 13 (1997).
36. J. F. McManus et al., Nature 371, 326 (1994).
37. We thank M.-P. Ledru for providing pollen data from Lagoa do Caçó, A. Suthhof for helpful comments, and A. Cremer and D. Dasbach for laboratory work. The manuscript benefited from the constructive criticism of two anonymous reviewers. This work was supported by the German Federal Ministry for Education and Research and by the DFG to H.B. Data are available at www.pangaea.de.