Publication Date:
2023-12-02
Description:
Knowledge of the evolution of North Atlantic Deep Water (NADW) is key to understanding the past evolution of the climatic system. 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.
Keywords:
306-U1314; AGE; COMPCORE; Composite Core; DEPTH, sediment/rock; Exp306; High-coerecivity component; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Isothermal Remanent Magnetization, intensity; Isothermal Remanent Magnetization, mean of gradient; Isothermal Remanent Magnetization, median of gradient; Isothermal Remanent Magnetization, mode of gradient; Joides Resolution; Low-coerecivity component; North Atlantic; North Atlantic Climate 2; Residual
Type:
Dataset
Format:
text/tab-separated-values, 1764 data points
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