Deep thermohaline Circulation in the low-latitude Atlantic during the Last Glacial ...

Present-day low-latitude eastern and western Atlantic basins are geochemically distinct below the sill depth of the Mid-Atlantic Ridge. While Antarctic Bottom Water (AABW) circulates freely in the western Atlantic, flow into the eastern Atlantic is restricted below 4 km which results in filling the...

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Bibliographic Details
Main Authors: Beveridge, N, Elderfield, Henry, Shackleton, Nicholas J
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA 1995
Subjects:
M25
Online Access:https://dx.doi.org/10.1594/pangaea.692007
https://doi.pangaea.de/10.1594/PANGAEA.692007
Description
Summary:Present-day low-latitude eastern and western Atlantic basins are geochemically distinct below the sill depth of the Mid-Atlantic Ridge. While Antarctic Bottom Water (AABW) circulates freely in the western Atlantic, flow into the eastern Atlantic is restricted below 4 km which results in filling the abyssal depths of this basin with water of geochemical similarity to nutrient depleted North Atlantic Deep Water. Using carbon isotopes and Cd/Ca ratios in benthic foraminifera we reconstruct the geochemistry of these basins during the last glacial maximum. Results indicate that deep eastern and western Atlantic basins became geochemically identical during the last glacial. This was achieved by shoaling of the upper surface of AABW above the sill depth of the Mid-Atlantic Ridge, which allowed bottom waters in both basins to be filled with the same water mass. Although AABW became the dominant water mass in the deep eastern Atlantic basin during the glacial, Holocene-glacial delta13C-PO4 shifts in this basin are in ... : Supplement to: Beveridge, N; Elderfield, Henry; Shackleton, Nicholas J (1995): Deep thermohaline circulation in the low-latitude Atlantic during the last glacial. Paleoceanography, 10(3), 643-660 ...