标题：Characteristics of the deep ocean carbon system during the past 150,000 years: ΣCO2 distributions, deep water flow patterns, and abrupt climate change
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1997
卷号：94
期号：16
页码：8300-8307
DOI：10.1073/pnas.94.16.8300
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Studies of carbon isotopes and cadmium in bottom-dwelling foraminifera from ocean sediment cores have advanced our knowledge of ocean chemical distributions during the late Pleistocene. Last Glacial Maximum data are consistent with a persistent high-{Sigma}CO2 state for eastern Pacific deep water. Both tracers indicate that the mid-depth North and tropical Atlantic Ocean almost always has lower {Sigma}CO2 levels than those in the Pacific. Upper waters of the Last Glacial Maximum Atlantic are more {Sigma}CO2-depleted and deep waters are {Sigma}CO2-enriched compared with the waters of the present. In the northern Indian Ocean, {delta}13C and Cd data are consistent with upper water {Sigma}CO2 depletion relative to the present. There is no evident proximate source of this {Sigma}CO2-depleted water, so I suggest that {Sigma}CO2-depleted North Atlantic intermediate/deep water turns northward around the southern tip of Africa and moves toward the equator as a western boundary current. At long periods (>15,000 years), Milankovitch cycle variability is evident in paleochemical time series. But rapid millennial-scale variability can be seen in cores from high accumulation rate series. Atlantic deep water chemical properties are seen to change in as little as a few hundred years or less. An extraordinary new 52.7-m-long core from the Bermuda Rise contains a faithful record of climate variability with century-scale resolution. Sediment composition can be linked in detail with the isotope stage 3 interstadials recorded in Greenland ice cores. This new record shows at least 12 major climate fluctuations within marine isotope stage 5 (about 70,000-130,000 years before the present).
