The marine δ18O record overestimates continental ice volume during Marine Isotope Stage 3Show others and affiliations
2022 (English)In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364, Vol. 212, p. 103814-103814, article id 103814Article in journal (Refereed) Published
Abstract [en]
There is disagreement in the Quaternary research community in how much of the marine δ18O signal is driven by change in ice volume. Here, we examine this topic by bringing together empirical and modelling work for Marine Isotope Stage 3 (MIS 3; 57 ka to 29 ka), a time when the marine δ18O record indicates moderate continental glaciation and a global mean sea level between −60 m and −90 m. We compile and interpret geological data dating to MIS 3 to constrain the extent of major Northern Hemisphere ice sheets (Eurasian, Laurentide, Cordilleran). Many key data, especially published in the past ~15 years, argue for an ice-free core of the formerly glaciated regions that is inconsistent with inferences from the marine δ18O record. We compile results from prior studies of glacial isostatic adjustment to show the volume of ice inferred from the marine δ18O record is unable to fit within the plausible footprint of Northern Hemisphere ice sheets during MIS 3. Instead, a global mean sea level between −30 m and − 50 m is inferred from geological constraints and glacial isostatic modelling. Furthermore, limited North American ice volumes during MIS 3 are consistent with most sea-level bounds through that interval. We can find no concrete evidence of large-scale glaciation during MIS 3 that could account for the missing ~30 m of sea-level equivalent during that time, which suggests that changes in the marine δ18O record are driven by other variables, including water temperature. This work urges caution regarding the reliance of the marine δ18O record as a de facto indicator of continental ice when few geological constraints are available, which underpins many Quaternary studies.
Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2022. Vol. 212, p. 103814-103814, article id 103814
Keywords [en]
Mid-Wisconsinan, Mid-Weichselian, Global mean sea level, Fennoscandian, Laurentide, Cordilleran
National Category
Other Earth and Related Environmental Sciences Geosciences, Multidisciplinary
Research subject
The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-4978DOI: 10.1016/j.gloplacha.2022.103814OAI: oai:DiVA.org:nrm-4978DiVA, id: diva2:1717493
Note
T.P. acknowledges funding from an NSF-EAR Postdoctoral Fellowship and UC President's Postdoc Program Fellowship. Field work innorthern Hudson Bay (Nunavut) is a contribution to Natural Resources Canada Geomapping for Energy and Minerals (GEM) Program (NRCancomribution number 20210064). E.J .G. was funded by Impuls- und Vernetzungsfonds, Helmholtz-Exzellenznetzwerke (grant no. ExNetOOOl-Phase 2-3) ''The Polar System and its Effects on the Ocean Floor(POSY)", Heimholtz Climate Ini tiative REKLIM (Regional Climate Change), a joint research project at the Heimholtz Association ofGerman research centers (HGF), the PACES-II program at the Alfred Wegener Institute and the Bundesministerium für Bildung und Forschungfunded project, PalMod, and a Japan Society for the Promotionof Science International Postdoctoral Research Fellowship. K.F.H. acknowledgesfunding from the Swedish Nuclear Fuel and Waste ManagementCompany (SKB). The authors acknowledge PALSEA, a working group of the International Union for Quaternary Sciences (INQUA) and Past Global Changes (PAGES), which in turn received support from theSwiss Academy of Sciences and the Chinese Academy of Sciences. Wethank Martin Roy and Pierre-Marc Godbout for constructive feedback, as weil as three anonymous reviewers. Finally, we thank the INQUA Dublin 2019 scientific committee for allowing us to present some aspects of ourwork in a session entitled: Estimates of Global Ice Volumes During MIS 3in Need of Re-Evaluation: A Multi-Disciplinary Approach.
2022-12-082022-12-08Bibliographically approved