Ice rafted debris, tetra-unsaturated alkenone and reconstructed sea surface temperature in sediment of ODP Hole 104-642B ...

• Main Authors: Bachem, Paul E, Risebrobakken, Bjørg, De Schepper, Stijn, McClymont, Erin L
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2016
• Subjects: Drilling/drill rig; Leg104; Joides Resolution; Bering Strait; Norwegian Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.865217; https://doi.pangaea.de/10.1594/PANGAEA.865217

The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST) and ice-rafted debris (IRD) in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major ... : Supplement to: Bachem, Paul E; Risebrobakken, Bjørg; De Schepper, Stijn; McClymont, Erin L (2017): Highly variable Pliocene sea surface conditions in the Norwegian Sea. Climate of the Past, 13, 1153-1168 ...