Persistent influence of precession on northern ice sheet variability since the early Pleistocene

International audience Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafti...

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Published in:Science
Main Authors: Barker, Stephen, Starr, Aidan, van der Lubbe, Jeroen, Doughty, Alice, Knorr, Gregor, Conn, Stephen, Lordsmith, Sian, Owen, Lindsey, Nederbragt, Alexandra, Hemming, Sidney, Hall, Ian, Levay, Leah, Berke, M, Brentegani, L., Caley, T., Cartagena-Sierra, A., Charles, C, Coenen, J, Crespin, J, Franzese, A, Gruetzner, J., Han, X., Hines, S, Jimenez Espejo, F, Just, J., Koutsodendris, A., Kubota, K., Lathika, N., Norris, R, Periera dos Santos, T., Robinson, R., Rolison, J, Simon, M, Tangunan, D., Yamane, M., Zhang, H.
Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2022
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Online Access:https://hal.science/hal-03796701
https://hal.science/hal-03796701/document
https://hal.science/hal-03796701/file/barker-et-al-2022-preprint.pdf
https://doi.org/10.1126/science.abm4033
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Summary:International audience Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafting within a given glacial cycle (reflecting ice sheet expansion) consistently occurred during times of decreasing obliquity whereas mass ice wasting (ablation) events were consistently tied to minima in precession. Furthermore, our results suggest that the ubiquitous association between precession-driven mass wasting events and glacial termination is a distinct feature of the mid to late Pleistocene. Before then (increasing), obliquity alone was sufficient to end a glacial cycle, before losing its dominant grip on deglaciation with the southward extension of Northern Hemisphere ice sheets since ~1 Ma.