Modelling evidence for late Eocene Antarctic glaciations

• Published in: Earth and Planetary Science Letters
• Main Authors: Van Breedam, Jonas, Huybrechts, Philippe, Crucifix, Michel
• Other Authors: UCL - SST/ELI/ELIC - Earth & Climate
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2022
• Subjects: Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geophysics; Antarctic; Paleoclimates; Oligocene; Tipping point; The Antarctic; Weddell Sea; Austral; Prydz Bay; Weddell; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/2078.1/268873; https://doi.org/10.1016/j.epsl.2022.117532

It is generally believed that a large scale Antarctic ice sheet formed at the Eocene-Oligocene transition (34.44-33.65 Ma). However, oxygen isotope excursions during the late Eocene (38-34 Ma) and geomorphic evidence of glacial erosion suggest that there were ephemeral continental scale glaciations before the Oi-1 event. Here, we investigate the Antarctic ice sheet evolution over a multi-million year timescale during the late Eocene up to the early Oligocene with the most recent estimates of carbon dioxide evolution over this time period and different bedrock elevation reconstructions. A novel ice sheet-climate modelling approach is applied where the Antarctic ice sheet model VUB-AISMPALEO is coupled to the emulated climate from HadSM3 using the coupler CLISEMv1.0. Our modelling results show that short-lived continental scale Antarctic glaciation might have occurred during the late Eocene when austral summer insolation reached a minimum in a narrow range of carbon dioxide concentrations. The Antarctic ice sheet first reached the coast in Prydz Bay and later in the Weddell Sea region, supporting the glaciomarine sediments dated prior to the EOT.