Glacial history of the Greenland Ice Sheet and a local ice cap in Qaanaaq, northwest Greenland
In this study, we present new information on the glacial history of the Greenland Ice Sheet (GrIS) and a local ice cap in Qaanaaq, northwest Greenland. We use geomorphological mapping, Be-10 exposure dating of boulders, analysis of lake cores, and C-14 dating of reworked marine molluscs and subfossi...
Published in: | Journal of Quaternary Science |
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Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2019
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Subjects: | |
Online Access: | https://pure.au.dk/portal/da/publications/glacial-history-of-the-greenland-ice-sheet-and-a-local-ice-cap-in-qaanaaq-northwest-greenland(6e9b2ca0-fd8c-4d60-8cd6-b8ffc63b444a).html https://doi.org/10.1002/jqs.3139 http://www.scopus.com/inward/record.url?scp=85071482215&partnerID=8YFLogxK |
Summary: | In this study, we present new information on the glacial history of the Greenland Ice Sheet (GrIS) and a local ice cap in Qaanaaq, northwest Greenland. We use geomorphological mapping, Be-10 exposure dating of boulders, analysis of lake cores, and C-14 dating of reworked marine molluscs and subfossil plants to constrain the glacial history. Our C-14 ages of reworked marine molluscs reveal that the ice extent in the area was at or behind its present-day position from 42.2 +/- 0.4 to 30.6 +/- 0.3k cal a BP after which the GrIS expanded to its maximum position during the Last Glacial Maximum. We find evidence of early ice retreat in the deep fjord (Inglefield Bredning) at 11.9 +/- 0.6 ka whereas the Taserssuit Valley was deglaciated similar to 4 ka later at 7.8 +/- 0.1k cal a BP. A proglacial lake record suggests that the local ice cap survived the Holocene Thermal Maximum but moss kill-dates reveal that it was smaller than present for a period of time before 3.3 +/- 0.1k until 0.9 +/- 0.1k cal a BP, following which the ice in the area expanded towards its Little Ice Age extent. Copyright (c) 2019 John Wiley & Sons, Ltd. |
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