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Absence of Cooling in New Zealand and the Adjacent Ocean During the Younger Dryas Chronozone Timothy T

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Absence of Cooling in New Zealand and the Adjacent Ocean During the Younger Dryas Chronozone Timothy T Absence of Cooling in New Zealand and the Adjacent Ocean During the Younger Dryas Chronozone Timothy T. Barrows, et al. Science 318, 86 (2007); DOI: 10.1126/science.1145873 The following resources related to this article are available online at www.sciencemag.org (this information is current as of October 24, 2007 ): Updated information and services, including high-resolution figures, can be found in the online version of this article at: http://www.sciencemag.org/cgi/content/full/318/5847/86 Supporting Online Material can be found at: http://www.sciencemag.org/cgi/content/full/318/5847/86/DC1 A list of selected additional articles on the Science Web sites related to this article can be found at: This article cites 30 articles, 4 of which can be accessed for free: http://www.sciencemag.org/cgi/content/full/318/5847/86#otherarticles This article appears in the following subject collections: on October 24, 2007 Atmospheric Science http://www.sciencemag.org/cgi/collection/atmos Information about obtaining reprints of this article or about obtaining permission to reproduce this article in whole or in part can be found at: http://www.sciencemag.org/about/permissions.dtl www.sciencemag.org Downloaded from Science (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. Copyright 2007 by the American Association for the Advancement of Science; all rights reserved. The title Science is a registered trademark of AAAS. REPORTS year between the Pacific and Nazca plates (23)]. slabs of the Izu-Bonin-Marianas and Tonga- 16. C. A. Finn, D. Moore, D. Damaske, T. Mackey, Geology We propose that subparallel subduction of the I-P Kermadec subduction zones. 27, 1087 (1999). 17. C. Gaina, R. D. Müller, B. Brown, T. Ishihara, S. Ivanov, mid-ocean ridge beneath Japan at 60 to 55 Ma The observed opposite bend geometries of Geophys. J. Int. 170, 151 (2007). resulted in nearly simultaneous slab break-off the Emperor-Hawaii seamount chain and the 18. D. T. Sandwell, W. H. F. Smith, Geophys. J. Int. 163,79 along the length of the Japanese trench (~2700 Pacific-Farallon fracture zones can be explained (2005). km). Geological observations from southern with combined absolute (relative to a fixed refer- 19. D. C. Engebretson, A. Cox, R. G. Gordon, Geol. Soc. Am. Spec. Pap. 206, 1 (1985). Japan support subduction of the I-P ridge and ence frame) and relative plate motions. Clock- 20. C. T. Onishi, G. Kimura, Tectonics 14, 1273 (1995). subsequent slab break-off at 60 to 55 Ma. wise rotation of eastern Pacific absolute plate 21. K. Otsuki, Island Arc 1, 51 (1992). Evidence includes cessation of a major accretion motion, combined with stable Farallon plate mo- 22. M. Brown, J. Metamorphic Geol. 16, 3 (1998). phase in the Late Cretaceous (24), emplacement tion (Fig. 4), results in a clockwise bend in 23. W. P. Schellart, J. Freeman, D. R. Stegman, L. Moresi, of the Okitsu Melange due to subduction of hot, Pacific-Farallon fracture zones at 53 to 49 Ma D. May, Nature 446, 308 (2007). 24. S. M. Agar, R. A. Cliff, I. R. Duddy, D. C. Rex, J. Geol. Soc. buoyant material at 55 Ma (24), and cross-cutting (16). In the western Pacific, a counterclockwise 146, 893 (1989). fault fabrics that indicate a counterclockwise change in absolute plate motion, from northwest 25. J. C. Lewis, T. B. Byrne, Tectonics 20, 548 (2001). rotation in relative plate motions between Eurasia to west due to Izanagi Ridge subduction (Fig. 4), 26. C. Gaina et al., J. Geophys. Res. 103, 12413 (1998). and the I-P plate, which are also consistent with combined with a sub-Pacific mantle flow slow- 27. C. E. Hall, M. Gurnis, M. Sdrolias, L. L. Lavier, R. D. Müller, Earth Planet. Sci. Lett. 212, 15 (2003). paleothermal and paleopressure data, between 55 down, results in the HEB. This conceptual model 28. W. H. F. Smith, D. T. Sandwell, J. Geophys. Res. 99, and 34 Ma (25). is testable via three-dimensional fully dynamic 21803 (1994). Rapid subduction of the I-P ridge, over a vast mantle flow simulations. 29. J.-Y. Royer, N. Rollet, Aust. J. Earth Sci. 44, 543 distance, triggered a chain reaction of tectonic (1997). 30. S. C. Cande, D. V. Kent, J. Geophys. Res. 100,6093 plate reorganizations. With complete subduction References and Notes (1995). of the I-P ridge at 55 Ma, forces acting on the 1. D. L. Anderson, Science 293, 2016 (2001). 31. G. Duclaux, P. Rey, S. Guillot, R. P. Ménot, Geology 35, Pacific changed from ridge-push to slab-pull, 2. M. Gurnis, C. Hall, L. Lavier, Geochem. Geophys. Geosyst. 715 (2007). which changed Pacific absolute plate motions 5, Q07001 (2004). 32. R. P. Ménot et al., in Antarctica: A Keystone in a Changing — 3. S. D. King, J. P. Lowman, C. W. Gable, Earth Planet. Sci. World Online Proceedings of the 10th ISAES, A. K. Cooper from northwest to west (Fig. 4). The change in et al., Eds. (USGS Open-File Rep. 2007-1047, Short Pacific plate motion caused cessation of Tasman Lett. 203, 83 (2002). 4. J. A. Tarduno et al., Science 301, 1064 (2003). Research Paper 048, 2007). Sea spreading at ~52 Ma (26). Increased slab pull 5. P. Molnar, J. Stock, Nature 327, 587 (1987). 33. We thank W. Smith for providing the downward continued gravity grid. Reviews by M. Gurnis and north of Australia, due to a westerly progression 6. B. Steinberger, R. Sutherland, R. J. O'Connell, Nature on October 24, 2007 430, 167 (2004). S. Cande, as well as detailed comments on early versions of the subducting Wharton Basin mid-ocean of the manuscript by P. Wessel, A. Dutkiewicz, and ridge (Fig. 4), changed Australian absolute plate 7. C. A. Finn, R. D. Müller, K. S. Panter, Geochem. Geophys. Geosyst. 6, Q02005 (2005). J. Stock, improved the manuscript considerably. We motion from northwest to north. A combination 8. D. A. Clague, G. B. Dalrymple, U.S. Geol. Surv. Prof. acknowledge the Ministry of Natural Resources of the of Australian and Pacific plate motion changes Paper 1350 (1987). Russian Federation and Geoscience Australia, who funded between 53 and 50 Ma initiated both the Tonga- 9. I. O. Norton, Tectonics 14, 1080 (1995). collection of some of the new marine magnetic data used in this work. Kermadec (2) subduction system and the Izu- 10. P. Wessel, Y. Harada, L. W. Kroenke, Geochem. Geophys. Geosyst. 7, Q03L12 (2006). Bonin-Marianas subduction systems, which 11. W. D. Sharp, D. A. Clague, Science 313, 1281 (2006). Supporting Online Material initiated likely before 50 Ma, due to convergence 12. S. C. Cande, E. M. Herron, B. R. Hall, Earth Planet. Sci. www.sciencemag.org/cgi/content/full/318/5847/83/DC1 Lett. 57, 63 (1982). across a fracture zone caused by the Pacific plate Fig. S1 www.sciencemag.org motion change (27). We suggest that the ob- 13. D. W. Caress, H. W. Menard, R. N. Hey, J. Geophys. Res. Tables S1 to S5 93, 2813 (1988). References served slowdown of sub-Pacific mantle flow at 14. P. F. Lonsdale, Bull. Geol. Soc. Am. 100, 733 (1988). 47 Ma (4) was due to progressive impediment of 15. A. A. Tikku, S. C. Cande, J. Geophys. Res. 104,661 13 April 2007; accepted 3 September 2007 lateral sub-Pacific mantle flow by the descending (1999). 10.1126/science.1143769 time scale (4) now place the event between Absence of Cooling in New Zealand ~12,900 and ~11,600 calendar years before the Downloaded from present (cal yr B.P.). Evidence for teleconnected and the Adjacent Ocean During the reversals of climate at this time occurs widely in the Northern Hemisphere (5), whereas the trans- fer of the Greenland climate stratigraphy to Ant- Younger Dryas Chronozone arctic ice cores via measurements of globally well-mixed atmospheric CH4 trapped within the 1 2 1 3 Timothy T. Barrows, * Scott J. Lehman, L. Keith Fifield, Patrick De Deckker ice show clearly that a deglacial reversal of cli- mate warming in Antarctica [the Antarctic Cold As the climate warmed at the end of the last glacial period, a rapid reversal in temperature, Reversal (ACR)] ended just as the Northern the Younger Dryas (YD) event, briefly returned much of the North Atlantic region to near full- Hemisphere YD began (6). The latter is con- glacial conditions. The event was associated with climate reversals in many other areas of the sistentwithanantiphasedrelationofclimate Northern Hemisphere and also with warming over and near Antarctica. However, the expression between Greenland and Antarctica seen earlier of the YD in the mid- to low latitudes of the Southern Hemisphere (and the southwest Pacific region in particular) is much more controversial. Here we show that the Waiho Loop advance of the 1Department of Nuclear Physics, Research School of Physical Franz Josef Glacier in New Zealand was not a YD event, as previously thought, and that the Sciences and Engineering, The Australian National University, adjacent ocean warmed throughout the YD. Canberra, ACT 0200, Australia. 2Institute of Arctic and Alpine Research and Department of Geological Sciences, University of 3 14 Colorado, Boulder, CO 80309, USA. Department of Earth and he Younger Dryas (YD) event was orig- tween 11,000 and 10,000 radiocarbon ( C) years Marine Sciences, The Australian National University, Canberra, inally recognized in Northern Europe and ago, an interval defined as the YD chronozone ACT 0200, Australia. the adjacent North Atlantic Ocean as an (1).
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