Arctic Ocean was covered by a shelf ice and filled with freshwater

Feb 6, 2021

An artist’s impression of a perspective from the glacial ocean interior, looking upward towards Iceland and the Faroe Islands, with Jan Mayen Island in the foreground and Greenland to the right. An ice shield from above restricts the narrow flow paths. Sunlight is absent at these depths, the light beams are just shown to illuminate the seafloor. Graphic: Alfred Wegener Institute / Martin Künsting

The Arctic Ocean was covered by up to 900 m thick shelf ice and was filled entirely with freshwater at least twice in the last 150,000 years. This surprising finding, reported in the latest issue of the journal Nature, is the result of long-term research by scientists from the Alfred Wegener Institute and the MARUM – Center for Marine Environmental Sciences at the University of Bremen.

With a detailed analysis of the composition of marine deposits, the scientists could demonstrate that the Arctic Ocean as well as the Nordic Seas did not contain sea-salt in at least two glacial periods. Instead, these oceans were filled with large amounts of freshwater under a thick ice shield. This water could then be released into the North Atlantic in very short periods of time. Such sudden freshwater inputs could explain rapid climate oscillations for which no satisfying explanation had been previously found.

Contact:

Prof. Dr. Rüdiger Stein
Arctic Ocean Paleoceanography
Phone: +49 421 218-65696
Email: [Bitte aktivieren Sie Javascript]

Original publication:

Walter Geibert, Jens Matthiessen, Ingrid Stimac, Jutta Wollenburg, Ruediger Stein: Glacial episodes of a freshwater Arctic Ocean covered by a thick ice shelf. Nature (2021), DOI: 10.1038/s41586-021-03186-y

Press release Alfred Wegener Institute