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Past interglacial climates with smaller ice sheets offer analogs for ice sheet response to future warming and contributions to sea level rise; however, well-dated geologic records from formerly ice-free areas are rare. Here we report that subglacial sediment from the Camp Century ice core preserves direct evidence that northwestern Greenland was ice free during the Marine Isotope Stage (MIS) 11 interglacial. Luminescence dating shows that sediment just beneath the ice sheet was deposited by flowing water in an ice-free environment 416 ± 38 thousand years ago. Provenance analyses and cosmogenic nuclide data and calculations suggest the sediment was reworked from local materials and exposed at the surface <16 thousand years before deposition. Ice sheet modeling indicates that ice-free conditions at Camp Century require at least 1.4 meters of sea level equivalent contribution from the Greenland Ice Sheet.
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Sub-ice sediment cosmogenic data Camp Century, Northwest Greenland, 1966 & 2022-2025
This data file contains the cosmogenic beryllium-10 (10Be), aluminum-26 (26Al), and chlorine-36 (36Cl) data from the frozen sediments underneath the Camp Century ice, produced at the Cosmogenic Nuclide Laboratory of the Lamont-Doherty Earth Observatory within National Science Foundation (NSF) Award 2114634 ('Collaborative Research: A fossil ecosystem under the ice: deciphering the glacialand vegetation history of northwest Greenland using long-lost Camp Century basal sediment'). These data help understanding the complexity of the 3 meters (m) of frozen sediment underneath the Camp Century ice core, and adds constraints to the question of past stability of this sector of the Greenland Ice Sheet. We have processed relatively small sub-samples we received from the University of Vermont team (lead PI Paul Bierman), by separating and de-contaminating quartz and feldspar, and measuring the cosmogenic isotopes listed above down the frozen sediment column. These important and complex data are currently prepared for publication under the lead of Lamont postdoc Joanna Charton.
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- Award ID(s):
- 2114634
- PAR ID:
- 10567653
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- cosmogenic nuclides Camp Century frozen sediments sub-ice archive
- Format(s):
- Medium: X Other: text/xml
- Location:
- Greenland
- Institution:
- Lamont-Doherty Earth Observatory of Columbia University
- Sponsoring Org:
- National Science Foundation
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