Evidence for two-step deglaciation and its impact on North Atlantic deep-water circulation

Oxygen and carbon isotope records from benthic and planktonic foraminifera are presented for the past 35,000 years in the northeastern Atlantic. The results support the idea that the last deglaci­ation took place in two major steps1–4, and conflict with theories calling for a strong reduction in North Atlantic deep-water formation to explain the abrupt cooling of the Younger Dryas cold period5–7.

[1]  P. Kroopnick.  The distribution of 13C of ΣCO2 in the world oceans , 1985 .

[2]  Wallace S. Broecker,et al.  Can the Greenland Climatic Jumps be Identified in Records from Ocean and Land? , 1988, Quaternary Research.

[3]  J. D. Hays,et al.  Variations in the Earth ' s Orbit : Pacemaker of the Ice Ages Author ( s ) : , 2022 .

[4]  A. Mcintyre,et al.  Ice-age thermal response and climatic role of the surface Atlantic Ocean, 40°N to 63°N , 1984 .

[5]  J. Overpeck,et al.  Climate change in the circum-North Atlantic region during the last deglaciation , 1989, Nature.

[6]  A. Mix,et al.  North Atlantic surface-ocean control of Pleistocene deep-ocean circulation , 1985 .

[7]  J. Kutzbach,et al.  The Influence of Changing Orbital Parameters and Surface Boundary Conditions on Climate Simulations for the Past 18 000 Years , 1986 .

[8]  E. Boyle.  The role of vertical chemical fractionation in controlling late Quaternary atmospheric carbon dioxide , 1988 .

[9]  Maureen E. Raymo,et al.  Matuyama 41,000-year cycles: North Atlantic Ocean and northern hemisphere ice sheets , 1986 .

[10]  L. Keigwin,et al.  Evidence from Fram Strait (78° N) for early deglaciation , 1988, Nature.

[11]  Laurent Labeyrie,et al.  Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation , 1988 .

[12]  N. Shackleton,et al.  Oxygen isotopes and sea level , 1986, Nature.

[13]  Edward A. Boyle,et al.  North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature , 1987, Nature.

[14]  R. Fairbanks,et al.  Carbon isotope composition of tropical surface water during the past 22,000 years , 1989 .

[15]  W. Berger,et al.  Sporadic shutdown of North Atlantic deep water production during the Glacial–Holocene transition? , 1986, Nature.

[16]  J. Duplessy,et al.  Variations in mode of formation and temperature of oceanic deep waters over the past 125,000 years , 1987, Nature.

[17]  W. Broecker,et al.  The chronology of the last deglaciation: implications to the cause of the Younger Dryas event , 1988 .

[18]  R. Fairbanks,et al.  Variability in the deep and intermediate water circulation of the Atlantic Ocean during the past 25,000 years: Northern Hemisphere modulation of the Southern Ocean , 1987 .

[19]  J. Duplessy,et al.  Deglacial warming of the northeastern Atlantic ocean: correlation with the paleoclimatic evolution of the european continent , 1981 .

[20]  W. Broecker,et al.  The impact of cold North Atlantic sea surface temperatures on climate: implications for the Younger Dryas cooling (11–10 k) , 1986 .

[21]  E. Jansen,et al.  Ocean circulation in the Norwegian sea during the last deglaciation: Isotopic evidence , 1985 .

[22]  D. Martinson,et al.  Late Pliocene variation in northern hemisphere ice sheets and North Atlantic deep water circulation , 1989 .

[23]  H. Oeschger,et al.  Lake Sediments as Continental δ18O Records from the Glacial/Post-Glacial Transition , 1984, Annals of Glaciology.

[24]  R. Fairbanks.  A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation , 1989, Nature.

[25]  J. Duplessy,et al.  Retreat velocity of the North Atlantic polar front during the last deglaciation determined by 14C accelerator mass spectrometry , 1987, Nature.

[26]  E. Boyle,et al.  Deep Circulation of the North Atlantic over the Last 200,000 Years: Geochemical Evidence , 1982, Science.

[27]  A. Mcintyre,et al.  The North Atlantic Ocean during the last deglaciation , 1981 .

[28]  Ola M. Johannessen,et al.  Mesoscale eddies in the Fram Strait marginal ice zone during the 1983 and 1984 Marginal Ice Zone Experiments , 1987 .

[29]  S. Manabe,et al.  The Influence of Continental Ice Sheets on the Climate of an Ice Age , 1985 .

[30]  J. Duplessy,et al.  Reconstruction of the last deglaciation: deconvolved records of δ18O profiles, micropaleontological variations and accelerator mass spectrometric14C dating , 1987 .

[31]  R. Fairbanks,et al.  The Marine Oxygen Isotope Record in Pleistocene Coral, Barbados, West Indies , 1978, Quaternary Research.

[32]  T. Hammen,et al.  Glacial sequence and environmental history in the Sierra Nevada del Cocuy (Colombia) , 1980 .

[33]  S. Häkkinen,et al.  A new mechanism for decreasing North Atlantic Deep Water production rates during the Pleistocene , 1988 .

[34]  J. Duplessy,et al.  Direct dating of the oxygen-isotope record of the last deglaciation by 14C accelerator mass spectrometry , 1986, Nature.

[35]  W. Broecker,et al.  Does the ocean–atmosphere system have more than one stable mode of operation? , 1985, Nature.

[36]  W. Broecker,et al.  Routing of meltwater from the Laurentide Ice Sheet during the Younger Dryas cold episode , 1989, Nature.

[37]  A. Mix,et al.  Structure and timing of the last deglaciation: Oxygen-isotope evidence☆ , 1985 .

[38]  J. Mangerud,et al.  A Younger Dryas Ash Bed in Western Norway, and Its Possible Correlations with Tephra in Cores from the Norwegian Sea and the North Atlantic , 1984, Quaternary Research.