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The Mode and Mechanism of the Last Deglaciation: Oceanic Evidence

Published online by Cambridge University Press:  20 January 2017

W. F. Ruddiman
Affiliation:
Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964
A. McIntyre
Affiliation:
Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 Queens College of the City University of New York, Flushing, New York 11367

Abstract

Changes in ocean temperature, carbonate productivity, and ice-rafted detritus in the North Atlantic suggest that half of the Northern Hemisphere ice volume at the last glacial maximum had disappeared by 13,000 yr B.P., despite the still-extensive limits of the ice sheets. This early thinning of the ice sheets occurred during a time when summer insolation values were slowly rising but when pollen evidence south of the ice margins indicates cold, dry air masses. We infer that this rapid early ice disintegration (16,000–13,000 yr B.P.) was caused by oceanic mechanisms: (1) rising sea level, causing increased calving along ice margins; (2) the chilling of the sea-surface by icebergs and meltwater, reducing moisture extraction by the atmosphere and transport to the ice sheets; and (3) winter freezing of the low-salinity meltwater layer, suppressing local moisture extraction and the regional influx of moisture-bearing storms from lower latitudes in winter and hence starving the ice sheets. These oceanic feedback mechanisms were strongest from 16,000 to 13,000 yr B.P., and weaker but still active from that date until the end of deglaciation at 6000 yr B.P.

Type
Original Articles
Copyright
University of Washington

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References

Adam, D.P. (1973). Ice ages and the thermal equilibrium of the earth. Journal Research U.S. Geological Survey 1. 587596.Google Scholar
Andrews, J.T. (1973). The Wisconsin Laurentide Ice Sheet: Dispersal centers, problems of rates of retreat, and climatic implications. Arctic and Alpine Research 5. 185199.Google Scholar
Andrews, J.T. (1975). Support for a stable late Wisconsin ice margin (14,000 to 9,000 B.P.): A test based on glacial rebound. Geology 4. 617620.2.0.CO;2>CrossRefGoogle Scholar
Andrews, J.T., Peltier, W.R. (1976). Collapse of the Hudson Bay ice center and glacio-eustatic rebound. Geology 4. 7376.Google Scholar
Andrews, J.T., Barry, R.G. (1978). Glacial inception and disintegration during the last glaciation. Annual Review Earth Planet Science 6. 205228.Google Scholar
Berger, A.L. (1978). Long-term variations of caloric insolation resulting from the earth's orbital elements. Quaternary Research 9. 139167.CrossRefGoogle Scholar
Bernabo, J.C., Webb, T. III (1977). Changing patterns in the Holocene pollen record of northeastern North America. Quaternary Research 8. 6496.Google Scholar
Bloom, A.L. (1971). Glacial-eustatic and isostatic controls of sea level since the last glaciation. InLate Cenozoic Glacial Ages.” (Turekian, K.K., Ed.) pp.355379. Yale University Press, New Haven.Google Scholar
Broecker, W.S. (1966). Absolute dating and the astronomical theory of glaciation. Science 151. 299304.CrossRefGoogle ScholarPubMed
Broecker, W.S., Ewing, M., Heezen, B.C. (1960). Evidence for an abrupt change in climate close to 11,000 years ago. American Journal of Science 258. 429440.Google Scholar
Broecker, W.S., van Donk, J. (1970). Insolation changes, ice volumes, and the O18 record in deep-sea cores. Reviews of Geophysics and Space Physics 8. 169198.CrossRefGoogle Scholar
Bryson, R.A., Wendland, W.M., Ives, J.D., Andrews, J.T. (1969). Radiocarbon isochrones on the disintegration of the Laurentide Ice Sheet. Arctic and Alpine Research 1. 114.Google Scholar
CLIMAP Project Members, . (1976). The surface of the ice-age earth. Science 191. 11311137.Google Scholar
Coope, G.R. (1977). Fossil coleopteran assemblages as sensitive indicators of climatic changes during the Devensian (last) cold stage. Philosophical Transactions of the Royal Society London B 280. 313337.Google Scholar
Davis, M.B. (1976). Pleistocene biogeography of temperate deciduous forests. Geoscience and Man 13. 1326.Google Scholar
Denton, G.H., Hughes, T. (1981). The Last Great Ice Sheets. Wiley Interscience Press, New York Google Scholar
Duplessy, J.-C. (1978). Isotope studies. InClimatic Change.” (Gribben, J., Ed.), pp. 4667. Cambridge University Press, Cambridge.Google Scholar
Duplessy, J.-C., Delibrias, G., Turon, J. L., Pujol, C., , and Duprat, J., (in press). Deglacial warming of the northeastern Atlantic Ocean. Correlation with the paleoclimatic evolution of the European continent. Palaeogeography, Palaeoclimatology, Palaeoecology.Google Scholar
Emiliani, C., Geiss, J. (1957). On glaciations and their causes. Geologische Rundschau 46. 576601.Google Scholar
Hammen, T. van der, Maarleveld, G.C., Vogel, J.C., Zagwijn, W.H. (1967). Stratigraphy, climatic succession, and radiocarbon dating of the last glacial in the Netherlands. Geologie En Mijnbouw 46. 7995.Google Scholar
Hare, F.K. (1976). Late Pleistocene and Holocene climates: Some persistent problems. Quaternary Research 6. 507517.Google Scholar
Hays, J.D., Imbrie, J., Shackleton, N.J. (1976). Variations in the earth's orbit: Pacemaker of the ice ages. Science 194. 11211131.CrossRefGoogle ScholarPubMed
Hollin, J.T. (1962). On the glacial history of Antarctica. Journal of Glaciology 4. 173195.Google Scholar
Hughes, T., Denton, G.H., Grosswald, M.G. (1977). Was there a late-Wu¨rm Arctic ice sheet?. Nature (London) 266. 596602.Google Scholar
Hutson, W.H. (1980). Bioturbation of deep-sea sediments: Oxygen isotopes and stratigraphic uncertainty. Geology 8. 127130.Google Scholar
Imbrie, J., Imbrie, J.Z. (1980). Modeling the climatic response to orbital variations. Science 207. 943953.Google Scholar
Iversen, J. (1954). The late-glacial flora of Denmark and its relation to climate and soil. Danmarks Geologisk Undersøgelse Ser. II 80. 87119.Google Scholar
Kennett, J.P., Shackleton, N.J. (1975). Laurentide Ice Sheet meltwater recorded in Gulf of Mexico deep-sea cores. Science 188. 147150.Google Scholar
Mangerud, J. (1977). Late Weichselian marine sediments containing shells, foraminifera, and pollen at Agotnes, western Norway. Norsk. Geologisk Tidsskrift 57. 2354.Google Scholar
McIntyre, A., Ruddiman, W.F., Jantzen, R. (1972). Southward penetrations of the North Atlantic polar front: Faunal and floral evidence of large-scale surface water mass movements over the last 225,000 years. Deep-Sea Research 19. 6177.Google Scholar
McIntyre, A., Kipp, N., Be´, A.W.H., Crowley, T., Gardner, J.V., Prell, W.L., Ruddiman, W.F. (1976). Glacial North Atlantic 18,000 years ago: A CLIMAP reconstruction. InInvestigation of Late Quarternary Paleo-Oceanography and Paleoclimatology.” (Cline, R.M., Hays, J.D., Ed.). pp. 4376. Geological Society of America Memoir 145. The Geological Society of America, Boulder.Google Scholar
Milankovitch, M.M. (1941). Canon of Insolation and the Ice-Age Problem. Ko¨niglich Serbische Akademie, BeogradEnglish translation by the Israel Program for Scientific Translations, published for the United States Department of Commerce and the National Science Foundation, Washington, D.C.Google Scholar
Pastouret, L., Chamley, H., Delibrias, G., Duplessy, J.-C., Thiede, J. (1978). Late Quaternary climatic changes in western tropical Africa deduced from deep-sea sedimentation off the Niger delta. Oceanologica Acta 1. 217232.Google Scholar
Paterson, W.S.B. (1972). Laurentide Ice Sheet: estimated volumes during late Wisconsin. Reviews of Geophysics and Space Physics 10. 885907.Google Scholar
Pennington, W. (1975). A chronostratigraphic comparison of Late-Weichselian and Late-Devensian subdivisions, illustrated by two radiocarbon-dated profiles from western Britain. Boreas 4. 157171.Google Scholar
Prest, V.K. (1969). Retreat of Wisconsin and recent ice in North America. Geological Survey of Canada Map 1257Awith textGoogle Scholar
Ruddiman, W.F. (1977). Late Quaternary deposition of ice-rafted sand in the subpolar North Atlantic (lat 40° to 65°N). Geological Society of America Bulletin 88. 18131827.Google Scholar
Ruddiman, W.F., McIntyre, A. (1973). Time-transgressive deglacial retreat of polar waters from the North Atlantic. Quaternary Research 3. 117130.Google Scholar
Ruddiman, W.F., McIntyre, A. (1976). Northeast Atlantic paleoclimatic changes over the last 600,000 years. InInvestigation of Late Quaternary Paleo-Oceanography and Paleoclimatology.Geological Society of America Memoir 145. (Cline, R.M., Hays, J.D., Ed.) pp. 199214. The Geological Society of America, Boulder.Google Scholar
Ruddiman, W.F., McIntyre, A. (1981). Oceanic mechanisms for amplification of the 23,000-ice-volume cycleyear Science 212. 617627.Google Scholar
Ruddiman, W. F., and McIntyre, A, . (in press). The North Atlantic Ocean during the last deglaciation. Palaeogeography, Palaeoclimatology, Palaeoecology.Google Scholar
Ruddiman, W.F., Sancetta, C.D., McIntyre, A. (1977). Glacial/interglacial response rate of subpolar North Atlantic waters to climatic change: The record left in deep-sea sediments. Philosophical Transactions of the Royal Society London B 280. 119142.Google Scholar
Ruddiman, W.F., Molfino, B., Esmay, A., Pokras, E. (1980). Evidence bearing on the mechanism of rapid Northern Hemisphere deglaciation. Climatic Change 3. 6587.Google Scholar
Stokes, W.L. (1955). Another look at the ice age. Science 122. 815821.Google Scholar
Watts, W.A. (1979). Late Quaternary vegetation of central Appalachia and the New Jersey coastal plain. Ecological Monographs 49. 427469.Google Scholar
Watts, W.A. (1980). Late Quaternary vegetation history at White Pond on the inner coastal plain of South Carolina. Quaternary Research 13. 187199.Google Scholar
Whitehead, D.R. (1967). Studies of full-glacial vegetation and climate in south-eastern United States. InQuaternary Paleoecology.” (Cushing, E.J., Wright, H.E. Jr., Ed.). pp. 237248. Yale University Press, New Haven.Google Scholar
Wright, H.E. Jr. (1977). Quaternary vegetation history—some comparisons between Europe and North America. Annual Review of Earth and Planetary Science 5. 123158.Google Scholar