Synchronous Deglacial Overturning and Water Mass Source Changes

Roberts, Natalie L. and Piotrowski, Alexander M. and McManus, Jerry F. and Keigwin, Lloyd D. (2010) Synchronous Deglacial Overturning and Water Mass Source Changes. Science, 327 (5961). pp. 75-78. DOI 10.1126/science.1178068

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Abstract

Understanding changes in ocean circulation during the last deglaciation is crucial to unraveling the dynamics of glacial-interglacial and millennial climate shifts. We used neodymium isotope measurements on postdepositional iron-manganese oxide coatings precipitated on planktonic foraminifera to reconstruct changes in the bottom water source of the deep western North Atlantic at the Bermuda Rise. Comparison of our deep water source record with overturning strength proxies shows that both the deep water mass source and the overturning rate shifted rapidly and synchronously during the last deglacial transition. In contrast, any freshwater perturbation caused by Heinrich event 1 could have only affected shallow overturning. These findings show how changes in upper-ocean overturning associated with millennial-scale events differ from those associated with whole-ocean deglacial climate events.

Item Type:	Article
Uncontrolled Keywords:	09AREP; IA59;
Subjects:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title:	Science
Volume:	327
Page Range:	pp. 75-78
Identification Number:	10.1126/science.1178068
Depositing User:	Sarah Humbert
Date Deposited:	05 Jan 2010 09:08
Last Modified:	23 Jul 2013 09:56
URI:	http://eprints.esc.cam.ac.uk/id/eprint/1287

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