Fairbanks
Richard G.
Fairbanks
Richard G.
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ArticleTiming of meltwater pulse 1a and climate responses to meltwater injections(American Geophysical Union, 2006-12-09) Stanford, Jennifer D. ; Rohling, Eelco J. ; Hunter, Sally E. ; Roberts, Andrew P. ; Rasmussen, Sune O. ; Bard, Edouard ; McManus, Jerry F. ; Fairbanks, Richard G.The temporal relationship between meltwater pulse 1a (mwp-1a) and the climate history of the last deglaciation remains a subject of debate. By combining the Greenland Ice Core Project δ 18O ice core record on the new Greenland ice core chronology 2005 timescale with the U/Th-dated Barbados coral record, we conclusively derive that mwp-1a did not coincide with the sharp Bølling warming but instead with the abrupt cooling of the Older Dryas. To evaluate whether there is a relationship between meltwater injections, North Atlantic Deep Water (NADW) formation, and climate change, we present a high-resolution record of NADW flow intensity from Eirik Drift through the last deglaciation. It indicates only a relatively minor 200-year weakening of NADW flow, coincident with mwp-1a. Our compilation of records also indicates that during Heinrich event 1 and the Younger Dryas there were no discernible sea level rises, and yet these periods were characterized by intense NADW slowdowns/shutdowns. Clearly, deepwater formation and climate are not simply controlled by the magnitude or rate of meltwater addition. Instead, our results emphasize that the location of meltwater pulses may be more important, with NADW formation being particularly sensitive to surface freshening in the Arctic/Nordic Seas.
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ArticleMarine04 marine radiocarbon age calibration, 0-26 cal kyr BP(Dept. of Geosciences, University of Arizona, 2004) Hughen, Konrad A. ; Baillie, Mike G. L. ; Bard, Edouard ; Beck, J. Warren ; Bertrand, Chanda J. H. ; Blackwell, Paul G. ; Buck, Caitlin E. ; Burr, George S. ; Cutler, Kirsten B. ; Damon, Paul E. ; Edwards, R. Lawrence ; Fairbanks, Richard G. ; Friedrich, Michael ; Guilderson, Thomas P. ; Kromer, Bernd ; McCormac, Gerry ; Manning, Sturt ; Bronk Ramsey, Christopher ; Reimer, Paula J. ; Reimer, Ron W. ; Remmele, Sabine ; Southon, John R. ; Stuiver, Minze ; Talamo, Sahra ; Taylor, F. W. ; van der Plicht, Johannes ; Weyhenmeyer, Constanze E.New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional 2000 yr, from 0–26 cal kyr BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision, and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically-dated tree-ring samples, converted with a box diffusion model to marine mixed-layer ages, cover the period from 0–10.5 cal kyr BP. Beyond 10.5 cal kyr BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific 14C reservoir age information to provide a single global marine mixed-layer calibration from 10.5–26.0 cal kyr BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the 14C age to calculate the underlying calibration curve (Buck and Blackwell, this issue). The marine data sets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring data sets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al. (this issue).
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ArticleIntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr BP(Dept. of Geosciences, University of Arizona, 2004) Reimer, Paula J. ; Baillie, Mike G. L. ; Bard, Edouard ; Bayliss, Alex ; Beck, J. Warren ; Bertrand, Chanda J. H. ; Blackwell, Paul G. ; Buck, Caitlin E. ; Burr, George S. ; Cutler, Kirsten B. ; Damon, Paul E. ; Edwards, R. Lawrence ; Fairbanks, Richard G. ; Friedrich, Michael ; Guilderson, Thomas P. ; Hogg, Alan G. ; Hughen, Konrad A. ; Kromer, Bernd ; McCormac, Gerry ; Manning, Sturt ; Bronk Ramsey, Christopher ; Reimer, Ron W. ; Remmele, Sabine ; Southon, John R. ; Stuiver, Minze ; Talamo, Sahra ; Taylor, F. W. ; van der Plicht, Johannes ; Weyhenmeyer, Constanze E.A new calibration curve for the conversion of radiocarbon ages to calibrated (cal) ages has been constructed and internationally ratified to replace IntCal98, which extended from 0–24 cal kyr BP (Before Present, 0 cal BP = AD 1950). The new calibration data set for terrestrial samples extends from 0–26 cal kyr BP, but with much higher resolution beyond 11.4 cal kyr BP than IntCal98. Dendrochronologically-dated tree-ring samples cover the period from 0–12.4 cal kyr BP. Beyond the end of the tree rings, data from marine records (corals and foraminifera) are converted to the atmospheric equivalent with a site-specific marine reservoir correction to provide terrestrial calibration from 12.4–26.0 cal kyr BP. A substantial enhancement relative to IntCal98 is the introduction of a coherent statistical approach based on a random walk model, which takes into account the uncertainty in both the calendar age and the 14C age to calculate the underlying calibration curve (Buck and Blackwell, this issue). The tree-ring data sets, sources of uncertainty, and regional offsets are discussed here. The marine data sets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed in brief, but details are presented in Hughen et al. (this issue a). We do not make a recommendation for calibration beyond 26 cal kyr BP at this time; however, potential calibration data sets are compared in another paper (van der Plicht et al., this issue).