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

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doi: 10.1002/2015GL063307
Author(s): Sato, Masahiko; Makio, Masato; Hayashi, Tatsuya; Ohno, Masao
Author Affiliation(s): Primary:
Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
Kyushu University, Japan
Mifune Dinosaur Museum, Japan
Volume Title: Geophysical Research Letters
Source: Geophysical Research Letters, 42(12), p.4949-4955. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276 CODEN: GPRLAJ
Note: In English. 34 refs.; illus., incl. sketch map
Summary: 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. Abstract Copyright (2015), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2015
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Cenozoic; Climate change; Expedition 306; Expeditions 303/306; IODP Site U1314; Integrated Ocean Drilling Program; JOIDES; Neogene; North Atlantic; North Atlantic Deep Water; Northeast Atlantic; Paleo-oceanography; Paleocirculation; Paleoclimatology; Pliocene; Tertiary; Upper Pliocene
Coordinates: N562200 N562200 W0275300 W0275300
Record ID: 2016057209
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom