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| Hoogakker, Babette A. A.; Chapman, Mark R.; Mccave, I. Nick; Hillaire-marcel, Claude; Ellison, Christopher R. W.; Hall, Ian R.; Telford, Richard J.. |
| High resolution flow speed reconstructions of two core sites located on Gardar Drift in the northeast Atlantic Basin and Orphan Knoll in the northwest Atlantic Basin reveal a long-term decrease in flow speed of Northeast Atlantic Deep Water (NEADW) after 6,500 years. Benthic foraminiferal oxygen isotopes of sites currently bathed in NEADW show a 0.2 parts per thousand depletion after 6,500 years, shortly after the start of the development of a carbon isotope gradient between NEADW and Norwegian Sea Deep Water. We consider these changes in near-bottom flow vigor and benthic foraminiferal isotope records to mark a significant reorganization of the Holocene deep ocean circulation, and attribute the changes to a weakening of NEADW flow during the mid to late... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33787/32562.pdf |
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| Tegzes, Andrea D.; Jansen, Eystein; Telford, Richard J.. |
| The coarseness of the 10-63 m terrigenous silt (i.e., sortable-silt) fraction tends to vary independently of sediment supply in current-sorted muds in the world's oceans, with coarser sediments representing relatively greater near-bottom flow speeds. Traditionally, the coarseness of this size fraction is described using an index called sortable-silt mean size ( SS), which is an arithmetic average calculated from the differential volume or mass distribution of grains within the 10-63 m terrigenous silt fraction, where the relative weights of the individual size bins become increasingly disproportionate, with respect to the actual number of grains within those size bins, toward the coarse end of the size range. This not only increases the absolute value of... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Paleo-current reconstructions; Sortable-silt mean size; Sortable-silt mean grain size; Coulter Counter. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00496/60728/65240.pdf |
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