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

• 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: UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (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
• Subjects: [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Ice Sheet; North Atlantic
• 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

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.