TY - JOUR
T1 - Abrupt intensification of North Atlantic Deep Water formation at the Nordic Seas during the late Pliocene climate transition
AU - Sato, Masahiko
AU - Makio, Masato
AU - Hayashi, Tatsuya
AU - Ohno, Masao
N1 - Publisher Copyright:
© 2015. American Geophysical Union. All Rights Reserved.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2015/6/28
Y1 - 2015/6/28
N2 - Knowledge of the evolution of North Atlantic Deep Water (NADW) is key to understanding the past evolution of the climatic system. Here we developed a new rock-magnetic method to determine the constituent magnetic minerals of sediments and report on the evolution of NADW during 2.2-2.9 Ma. We measured isothermal remanence acquisition curves of North Atlantic deep-sea sediments drilled at the Gardar Drift and decomposed the first derivatives of these curves into high-coercivity and low-coercivity components. Residuals of the decomposition were sufficiently small throughout the study interval, confirming that the Gardar Drift sediments represent a mixing of the two end-members. Fractional changes of the high-coercivity component represent variation of the Iceland-Scotland Overflow Water, a branch of NADW formed at the Nordic Seas. The high-coercivity component increased significantly during an interglacial period just after ∼2.68 Ma, which suggests that NADW formation in the Nordic Seas abruptly intensified at this time.
AB - Knowledge of the evolution of North Atlantic Deep Water (NADW) is key to understanding the past evolution of the climatic system. Here we developed a new rock-magnetic method to determine the constituent magnetic minerals of sediments and report on the evolution of NADW during 2.2-2.9 Ma. We measured isothermal remanence acquisition curves of North Atlantic deep-sea sediments drilled at the Gardar Drift and decomposed the first derivatives of these curves into high-coercivity and low-coercivity components. Residuals of the decomposition were sufficiently small throughout the study interval, confirming that the Gardar Drift sediments represent a mixing of the two end-members. Fractional changes of the high-coercivity component represent variation of the Iceland-Scotland Overflow Water, a branch of NADW formed at the Nordic Seas. The high-coercivity component increased significantly during an interglacial period just after ∼2.68 Ma, which suggests that NADW formation in the Nordic Seas abruptly intensified at this time.
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U2 - 10.1002/2015GL063307
DO - 10.1002/2015GL063307
M3 - Article
AN - SCOPUS:84946811480
VL - 42
SP - 4949
EP - 4955
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 12
ER -