Ice sheet-free West Antarctica during peak early Oligocene glaciation

• 成果类型: Article
• 署名作者: Klages, J. P.; Hillenbrand, C. D.; Bohaty, S. M.; Salzmann, U.; Bickert, T.; Lohmann, G.; Knahl, H. S.; Gierz, P.; Niu, L.; Titschack, J.; Kuhn, G.; Frederichs, T.; Mueller, J.; Bauersachs, T.; Larter, R. D.; Hochmuth, K.; Ehrmann, W.; Nehrke, G.; Rodriguez-Tovar, F. J.; Schmiedl, G.; Spezzaferri, S.; Laeufer, A.; Lisker, F.; van de Flierdt, T.; Eisenhauer, A.; Uenzelmann-Neben, G.; Esper, O.; Smith, J. A.; Paelike, H.; Spiegel, C.; Dziadek, R.; Ronge, T. A.; Freudenthal, T.; Gohl, K.
• 署名单位: Helmholtz Association; Alfred Wegener Institute, Helmholtz Centre for Polar & Marine Research; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC British Antarctic Survey; Ruprecht Karls University Heidelberg; Northumbria University; University of Bremen; University of Bremen; University of Bremen; RWTH Aachen University; University of Tasmania; Leipzig University; University of Granada; University of Hamburg; University of Fribourg; Imperial College London; Helmholtz Association; GEOMAR Helmholtz Center for Ocean Research Kiel; Texas A&M University System; Texas A&M University College Station
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10391
• DOI: 10.1126/science.adj3931
• 发表日期: 2024-07-19
• 页码: 322-327
• 关键词: amundsen sea embayment; dialkyl glycerol tetraethers; offshore wilkes land; temperature-dependence; eocene; climate; sediments; record; marine; lipids

摘要

One of Earth's most fundamental climate shifts, the greenhouse-icehouse transition 34 million years ago, initiated Antarctic ice sheet buildup, influencing global climate until today. However, the extent of the ice sheet during the Early Oligocene Glacial Maximum (similar to 33.7 to 33.2 million years ago) that immediately followed this transition-a critical knowledge gap for assessing feedbacks between permanently glaciated areas and early Cenozoic global climate reorganization-is uncertain. In this work, we present shallow-marine drilling data constraining earliest Oligocene environmental conditions on West Antarctica's Pacific margin-a key region for understanding Antarctic ice sheet evolution. These data indicate a cool-temperate environment with mild ocean and air temperatures that prevented West Antarctic Ice Sheet formation. Climate-ice sheet modeling corroborates a highly asymmetric Antarctic ice sheet, thereby revealing its differential regional response to past and future climatic change.