Northern-sourced water dominated the Atlantic Ocean during the Last Glacial Maximum

Details

Serval ID
serval:BIB_038C80656E5B
Type
Article: article from journal or magazin.
Collection
Publications
Title
Northern-sourced water dominated the Atlantic Ocean during the Last Glacial Maximum
Journal
Geology
Author(s)
Pöppelmeier F., Blaser P., Gutjahr M., Jaccard S.L., Frank M., Max L., Lippold J.
ISSN
0091-7613
1943-2682
Publication state
Published
Issued date
01/08/2020
Peer-reviewed
Oui
Volume
48
Number
8
Pages
826-829
Language
english
Abstract
Increased carbon sequestration in the ocean subsurface is commonly assumed to have been one of the main causes responsible for lower glacial atmospheric CO2 concentrations. Remineralized carbon must have been stored away from the atmosphere for thousands of years, yet the water mass structure accommodating such increased carbon storage continues to be debated. Here, we present new sediment-derived bottom-water neodymium isotope records that allow fingerprinting of water masses and provide a more complete picture of the Atlantic Meridional Overturning Circulation geometry during the Last Glacial Maximum. These results suggest that the vertical and meridional structure of the Atlantic water mass distribution only experienced minor changes since the last ice age. In particular, we find no compelling evidence supporting glacial southern-sourced water substantially expanding to shallower depths and farther into the Northern Hemisphere than today, which had been previously inferred from stable carbon isotope (δ13C) reconstructions. We argue that depleted δ13C values observed in the deep Northwest Atlantic do not necessarily indicate the presence of southern-sourced water. Instead, these values may represent a northern-sourced water mass with lower than modern preformed δ13C values that were further modified downstream by increased sequestration of remineralized carbon, facilitated by a more sluggish glacial deep circulation, corroborating previous evidence.
Keywords
Arctic Ocean, Atlantic Meridional Overturning Circulation, C-13/C-12, carbon, Cenozoic, cores, Holocene, isotope ratios, last glacial maximum, marine sediments, metals, models, Nd-144/Nd-143
Web of science
Create date
06/09/2021 14:45
Last modification date
12/07/2024 9:40
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