Closure of the Bering Strait caused Mid-Pleistocene Transition cooling

Kender, Sev; Ravelo, Ana Christina; Worne, Savannah; Swann, George E. A.; Leng, Melanie J.; Asahi, Hirofumi; Becker, Julia; Detlef, Henrieka; Aiello, Ivano W.; Andreasen, Dyke; Hall, Ian R.

Abstract

The Mid-Pleistocene Transition (MPT) is characterised by cooling and lengthening glacial cycles from 600–1200 ka, thought to be driven by reductions in glacial CO2 in particular from ~900 ka onwards. Reduced high latitude upwelling, a process that retains CO2 within the deep ocean over glacials, could have aided drawdown but has so far not been constrained in either hemisphere over the MPT. Here, we find that reduced nutrient upwelling in the Bering Sea, and North Pacific Intermediate Water expansion, coincided with the MPT and became more persistent at ~900 ka. We propose reduced upwelling was controlled by expanding sea ice and North Pacific Intermediate Water formation, which may have been enhanced by closure of the Bering Strait. The regional extent of North Pacific Intermediate Water across the subarctic northwest Pacific would have contributed to lower atmospheric CO2 and global cooling during the MPT.

Citation

Kender, S., Ravelo, A. C., Worne, S., Swann, G. E. A., Leng, M. J., Asahi, H., Becker, J., Detlef, H., Aiello, I. W., Andreasen, D., & Hall, I. R. (2018). Closure of the Bering Strait caused Mid-Pleistocene Transition cooling. Nature Communications, 9(1), Article 5386. https://doi.org/10.1038/s41467-018-07828-0

• Journal Article Type: Article
• Acceptance Date: Nov 28, 2018
• Online Publication Date: Dec 19, 2018
• Publication Date: Dec 19, 2018
• Deposit Date: Dec 19, 2018
• Publicly Available Date: Dec 19, 2018
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: 5386
• DOI: https://doi.org/10.1038/s41467-018-07828-0
• Keywords: General Biochemistry, Genetics and Molecular Biology; General Physics and Astronomy; General Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/1426143
• Publisher URL: https://www.nature.com/articles/s41467-018-07828-0