Is modern Arctic Ocean circulation exceptional?

• Main Author: Frank, Martin
• Format: Article in Journal/Newspaper
• Language: English
• Published: IFM-GEOMAR 2008
• Subjects: Arctic; Arctic Ocean; Fram Strait; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/15459/; https://oceanrep.geomar.de/id/eprint/15459/1/Frank%20ifm-geomar-annual-report-2007-2.pdf; http://www.geomar.de/fileadmin/content/service/presse/public-pubs/ifm-geomar-report-2007.pdf

Arctic Ocean circulation as we know it today is an exceptional situation compared with the geological past. This was shown from geochemical analyses of a unique marine sediment core recovered in the central Arctic Ocean. A major transition from oxygen-poor sediments to well oxygenated sediments 17.3 million years ago indicates that the Fram Strait, which is the only deep water connection of the Arctic Ocean with the Atlantic Ocean, already opened at this time and allowed the establishment of a well-ventilated ocean basin. Isotope geochemical results suggest that the Arctic deep circulation was strongly influenced by sea ice formation during most of the past 15 million years and was not predominantly controlled by inflowing Atlantic waters, as is the case today.