Glacial history of the Greenland Ice Sheet and a local ice cap in Qaanaaq, northwest Greenland

• Published in: Journal of Quaternary Science
• Main Authors: Søndergaard, Anne Sofie, Larsen, Nicolaj Krog, Olsen, Jesper, Strunk, Astrid, Woodroffe, Sarah
• Other Authors: Aarhus Universitets Forskningsfond, Villum Fonden
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: Greenland; Inglefield Bredning; Qaanaaq; Ice cap; Ice Sheet
• Online Access: http://dx.doi.org/10.1002/jqs.3139; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.3139; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3139; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jqs.3139

ABSTRACT 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, 10 Be exposure dating of boulders, analysis of lake cores, and 14 C dating of reworked marine molluscs and subfossil plants to constrain the glacial history. Our 14 C 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 ~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 © 2019 John Wiley & Sons, Ltd.