05.12.2024 New insights into eccentricity pacing and rapid termination of the early Antarctic ice ages

What was the influence of cyclic changes in Earth’s orbital parameters on the dynamic of continental ice sheets under a warmer-than-present climate scenario? This question has been tackled by an international research team from the UK, Germany, Norway and the US under strong participation of Heidelberg geoscientists. Based on geochemical investigations on microscopic shells from a deep-sea sediment core in the North Atlantic the researchers gain new insights into the dynamics of the Antarctic ice sheet under a unipolar glaciated climate with higher-than-today CO2 levels. The data further allow a detailed insight into the fundamental processes underlying the dynamic of the Antarctic ice sheet in the early Oligocene. For their study, the scientists obtained geochemical data from sediment samples that allowed a detailed reconstruction of ice volume fluctuations and their cyclicity for the period 20-28 million years ago. The results show, that the Late Oligocene to Early Miocene Antarctic continental ice sheet was mainly triggered by Earth’s eccentricity but was very vulnerable so that even small changes in the climate system could trigger short-term melting if the ice sheet. The research results were published in the journal “Nature Communications”.