Age determination and n-Alkane concentration of Arctic Ocean sediment cores

We have reconstructed the surface water environment of the Arctic Ocean over the last ~ 50,000 years using measurements of the organic nitrogen and carbon isotope ratios, carbonate and total organic carbon concentrations (TOC), and terrestrial biomarkers (lignin and long-chain n-alkanes) in four mul...

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Bibliographic Details
Main Authors: Schubert, Carsten J, Stein, Ruediger, Calvert, Stephen E
Format: Other/Unknown Material
Language:English
Published: PANGAEA 2001
Subjects:
AWI_Paleo
Paleoenvironmental Reconstructions from Marine Sediments @ AWI
Arctic
Arctic Ocean
Foraminifera*
Phytoplankton
Southern Ocean
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.847782
https://doi.org/10.1594/PANGAEA.847782
Description
Summary:We have reconstructed the surface water environment of the Arctic Ocean over the last ~ 50,000 years using measurements of the organic nitrogen and carbon isotope ratios, carbonate and total organic carbon concentrations (TOC), and terrestrial biomarkers (lignin and long-chain n-alkanes) in four multicores. Variations in nitrogen isotope ratios that are concordant with TOC and carbonate concentrations (representing foraminifera and excluding ice-rafted-debris) reflect differences in relative nutrient utilization of phytoplankton in the surface waters. However, d15N variations also appear to be dependent on the stratification of the water column and therefore potentially track the exchange of nutrients between deep and surface waters. Low Last Glacial Maximum (LGM) d15N values and higher Holocene values are opposite to those recorded in the Southern Ocean. The Arctic Ocean with higher nutrient utilization today compared to the LGM therefore acts as a counterpart to the Southern Ocean, although the global impact on carbon dioxide variations compared to the Southern Ocean is probably low.

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