Recovery of unique geological samples sheds light on formation of today’s Antarctic ice sheet

Recovery of unique geological samples sheds light on formation of ...

In recent years, global warming has left its mark on the Antarctic ice sheets. The “eternal” ice in Antarctica is melting faster than previously assumed, particularly in West Antarctica more than East Antarctica. The root for this could lie in its formation, as an international research team led by the Alfred Wegener Institute has now discovered.

Sediment samples from drill cores combined with complex climate and ice-sheet modeling show that permanent glaciation of Antarctica began around 34 million years ago—but did not encompass the entire continent as previously assumed, but rather was confined to the eastern region of the continent (East Antarctica). It was not until at least 7 million years later that ice was able to advance towards the West Antarctic coast.

The results of the new study show how substantially differently East and West Antarctica react to external forcing, as the researchers describe in the journal Science.

Around 34 million years ago, our planet underwent one of the most fundamental climate shifts that still influences global climate conditions today: the transition from a greenhouse world (with no or very little accumulation of continental ice) to an icehouse world (with large permanently glaciated areas). During this time, the Antarctic ice sheet built up. How, when, and above all, where were not yet known due to a lack of reliable data and samples from key regions, especially from West Antarctica, that documented the changes in the past.

Researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now been able to close this knowledge gap, together with colleagues from the British Antarctic Survey, Heidelberg University, Northumbria University (UK), and the MARUM—Center for Marine Environmental Sciences at the University of Bremen, in addition to collaborators from the Universities in Aachen, Leipzig, Hamburg, Bremen, and Kiel, as well as the University of Tasmania (Australia), Imperial College London (UK), Université de Fribourg (Switzerland), Universidad de Granada (Spain), Leicester University (UK), Texas A&M University (U.S.), Senckenberg am Meer, and the Federal Institute for Geosciences and Natural Resources in Hanover, Germany.

Based on a drill core that the researchers

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