Abrupt intensification of North Atlantic Deep Water formation at the Nordic Seas during the late Pliocene climate transition

Masahiko Sato, Masato Makio, Tatsuya Hayashi, Masao Ohno

Research output: Contribution to journalArticle

4 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)4949-4955
Number of pages7
JournalGeophysical Research Letters
Issue number12
Publication statusPublished - Jun 28 2015


All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth and Planetary Sciences(all)

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