Aarhus University Seal

Christof Pearce

Northeast Greenland: ice-free shelf edge at 79.4 degrees N around the Last Glacial Maximum 25.5-17.5 ka

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

DOI

The size of the last glacial ice sheet on the Northeast (NE) Greenland shelf and its interaction with ocean circulation have been the subject of debate. Here we provide insights into the extent of the ice sheet around the Last Glacial Maximum (LGM) and investigate timing and strength of changes in the flow of Atlantic Water. The study is based on a multiproxy investigation of a marine sediment core, gravity core DA17-NG-ST01-019G, from 323-m water depth at the NE Greenland shelf edge at 79.4°N. We present benthic and planktic foraminiferal distribution data, AMS-14C dates, sedimentological (ice-rafted debris (IRD) and grain sizes), and geochemical (XRF) data in combination with geophysical (sub-bottom profiler) data. The oldest sediments at the study site are dated to 25.5–17.5 ka, encompassing the time frame from the beginning of the LGM to the early deglaciation. This part is overlain by sediments from the late deglaciation and Holocene. The deposits dating from the LGM are very rich in both planktic and benthic foraminifera and macrofossils of excellent preservation. The faunas show that the site generally was affected by a strong flow of relatively warm subsurface Atlantic Water during the LGM and Early Holocene. Conditions turned more polar with cold bottom water flow in the Middle–Late Holocene (c. 7.5 ka to Recent) with presence of mainly agglutinated benthic foraminiferal species. Our data from the LGM also indicate that the deposits were mixed by iceberg scouring, confirmed by the geophysical data showing extensive ploughing of the sediments on the outer shelf area. The results further indicate that the Greenland Ice Sheet did not reach to the edge of the NE Greenland shelf at 79.4°N during the LGM 24–18 ka.

Original languageEnglish
JournalBoreas
Volume51
Issue4
Pages (from-to)759-775
Number of pages17
ISSN0300-9483
DOIs
Publication statusPublished - Oct 2022

Bibliographical note

Publisher Copyright:
© 2022 The Authors. Boreas published by John Wiley & Sons Ltd on behalf of The Boreas Collegium.

    Research areas

  • ARCTIC-OCEAN, ATLANTIC WATER, BENTHIC FORAMINIFERA, CALCIUM-CARBONATE DISSOLUTION, ENVIRONMENTAL-CHANGE, FRAM STRAIT, NORDIC SEAS, SCORESBY-SUND, SEA-ICE, SHEET MASS-BALANCE

See relations at Aarhus University Citationformats

ID: 279925924