Sedimentology and Nd isotope ratios of sediment core PS72/410-1

The freshwater budget of the Arctic Ocean is a key component governing the deep water formation in the North Atlantic and the global climate system. We analyzed the isotopic composition of neodymium (epsilon-Nd) in authigenic phases of marine sediments on the Mendeleev Ridge in the western Arctic Oc...

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Bibliographic Details
Main Authors: Jang, Kwangchul, Han, Yeongcheol, Huh, Youngsook, Nam, Seung-Il, Stein, Ruediger, Mackensen, Andreas, Matthiessen, Jens
Format: Dataset
Language:English
Published: PANGAEA 2013
Subjects:
Arctic Ocean
ARK-XXIII/3
AWI_Paleo
Giant box corer
GKG
Paleoenvironmental Reconstructions from Marine Sediments @ AWI
Polarstern
PS72
PS72/410-1
Arctic
Ice Sheet
NADW
North Atlantic
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.817616
https://doi.org/10.1594/PANGAEA.817616
Description
Summary:The freshwater budget of the Arctic Ocean is a key component governing the deep water formation in the North Atlantic and the global climate system. We analyzed the isotopic composition of neodymium (epsilon-Nd) in authigenic phases of marine sediments on the Mendeleev Ridge in the western Arctic Ocean spanning an estimated time interval from present to about 75 ka BP. This continuous record was used to reconstruct the epsilon-Nd of the polar deep water (PDW) and changes in freshwater sources to the PDW through time. Three deviations in epsilon-Nd from a long term average of -10.2 were identified at estimated 46-51, 35-39 and 13-21 ka BP. The estimated 46-51 ka BP event can be traced to bursting of ice-dammed lakes accompanying the collapse of the Barents-Kara Ice Sheet, which would have released radiogenic Nd to the eastern Arctic Ocean. The cyclonic surface circulation in the eastern Arctic Ocean must have been stronger than at present for the event to be recorded on the Mendeleev Ridge. For the 35-39 and 13-21 ka BP events, it is likely that the Laurentide Ice Sheet (LIS) supplied the unradiogenic freshwater. The configuration of the anticyclonic circulation in the western Arctic was probably similar to today or expanded eastward. Our simple mass balance calculations suggest that large amounts of freshwater were released but due to significant deep water formation within the Arctic Ocean, the effect on the formation of NADW was probably minor.

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