Grain size analysis of ODP Site 162-984

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Hauptverfasser: Praetorius, Summer K, McManus, Jerry F, Oppo, Delia W, Curry, William B
Format: Dataset Open Access
Sprache:en
Veröffentlicht: PANGAEA 2008
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author Praetorius, Summer K
McManus, Jerry F
Oppo, Delia W
Curry, William B
author_facet Praetorius, Summer K
McManus, Jerry F
Oppo, Delia W
Curry, William B
collection Datos científicos de ciencias marinas y ambientales
contents Past changes in the freshwater balance of the surface North Atlantic Ocean are thought to have influenced the rate of deep-water formation, and consequently climate (Broecker and Denton, 1989, doi:10.1016/0016-7037(89)90123-3; Manabe and Stouffer, 1996; doi:10.1038/378165a0). Although water-mass proxies are generally consistent with an impact of freshwater input on meridional overturning circulation (Boyle and Keigwin, 1987, doi:10.1038/330035a0), there has been little dynamic evidence to support this linkage. Here we present a 25,000 year record of variations in sediment grain size from south of Iceland, which indicates vigorous bottom-water currents during both the last glacial maximum and the Holocene period. Together with reconstructions of North Atlantic water-mass distribution, vigorous bottom currents suggest a shorter residence time of northern-source waters during the last glacial maximum, relative to the Holocene period. The most significant reductions in flow strength occur during periods that have been associated with freshening of the surface North Atlantic. The short-term deglacial oscillations in bottom current strength are closely coupled to changes in Greenland air temperature, with a minimum during the Younger Dryas cold reversal and a maximum at the time of rapid warming at the onset of the Holocene. Our results support a strong connection between ocean circulation and rapid climate change.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_769648
institution PANGAEA
language en
publishDate 2008
publisher PANGAEA
record_format pangaea
spellingShingle Grain size analysis of ODP Site 162-984
Praetorius, Summer K
McManus, Jerry F
Oppo, Delia W
Curry, William B
162-984; COMPCORE; Composite Core; Joides Resolution; Leg162; North Atlantic Ocean; Ocean Drilling Program; ODP
Past changes in the freshwater balance of the surface North Atlantic Ocean are thought to have influenced the rate of deep-water formation, and consequently climate (Broecker and Denton, 1989, doi:10.1016/0016-7037(89)90123-3; Manabe and Stouffer, 1996; doi:10.1038/378165a0). Although water-mass proxies are generally consistent with an impact of freshwater input on meridional overturning circulation (Boyle and Keigwin, 1987, doi:10.1038/330035a0), there has been little dynamic evidence to support this linkage. Here we present a 25,000 year record of variations in sediment grain size from south of Iceland, which indicates vigorous bottom-water currents during both the last glacial maximum and the Holocene period. Together with reconstructions of North Atlantic water-mass distribution, vigorous bottom currents suggest a shorter residence time of northern-source waters during the last glacial maximum, relative to the Holocene period. The most significant reductions in flow strength occur during periods that have been associated with freshening of the surface North Atlantic. The short-term deglacial oscillations in bottom current strength are closely coupled to changes in Greenland air temperature, with a minimum during the Younger Dryas cold reversal and a maximum at the time of rapid warming at the onset of the Holocene. Our results support a strong connection between ocean circulation and rapid climate change.
title Grain size analysis of ODP Site 162-984
topic 162-984; COMPCORE; Composite Core; Joides Resolution; Leg162; North Atlantic Ocean; Ocean Drilling Program; ODP
url https://doi.org/10.1594/PANGAEA.769648