1. Ice sheet–free West Antarctica during peak early Oligocene glaciation
- Author
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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., Müller, J., Bauersachs, T., Larter, R.D., Hochmuth, K., Ehrmann, W., Nehrke, G., Rodríguez-Tovar, F.J., Schmiedl, G., Spezzaferri, S., Läufer, A., Lisker, F., van de Flierdt, T., Eisenhauer, A., Uenzelmann-Neben, G., Esper, O., Smith, J.A., Pälike, H., Spiegel, C., Dziadek, R., Ronge, T.A., Freudenthal, T., Gohl, K., 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., Müller, J., Bauersachs, T., Larter, R.D., Hochmuth, K., Ehrmann, W., Nehrke, G., Rodríguez-Tovar, F.J., Schmiedl, G., Spezzaferri, S., Läufer, A., Lisker, F., van de Flierdt, T., Eisenhauer, A., Uenzelmann-Neben, G., Esper, O., Smith, J.A., Pälike, H., Spiegel, C., Dziadek, R., Ronge, T.A., Freudenthal, T., and Gohl, K.
- Abstract
One of Earth’s most fundamental climate shifts – the greenhouse-icehouse transition 34 Ma ago – initiated Antarctic ice-sheet build-up, influencing global climate until today. However, the extent of the ice sheet during the Early Oligocene Glacial Maximum (~33.7–33.2 Ma) that immediately followed this transition, a critical knowledge gap for assessing feedbacks between permanently glaciated areas and early Cenozoic global climate reorganization, is uncertain. Here, 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 preventing 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.
- Published
- 2024