Assessing ice margin fluctuations on differing timescales: Chronological constraints from Sermeq Kujatdleq and Nordenskiöld Gletscher, central West Greenland ...

• Main Authors: Kelley, Samuel E, Briner, Jason P, O’Hara, Sandy L
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Figshare 2018
• Subjects: Geography; History; Greenland; Ice Sheet
• Online Access: https://dx.doi.org/10.25384/sage.c.4048568; https://figshare.com/collections/Assessing_ice_margin_fluctuations_on_differing_timescales_Chronological_constraints_from_Sermeq_Kujatdleq_and_Nordenski_ld_Gletscher_central_West_Greenland/4048568

The observational record of ice margin position reveals asynchrony in both the timing and magnitude of Greenland Ice Sheet (GrIS) margin fluctuations and illustrates the complex reactions of ice sheets to climatic perturbations. In this study, we reconstruct the timing and pattern of middle- and late-Holocene GrIS margin fluctuations at two locations, ~190 km apart, in central West Greenland using radiocarbon-dated sediment cores from proglacial-threshold lakes. Our results demonstrate that deglaciation occurs at both sites during the early Holocene, with the ice sheet remaining in a smaller-than-present ice margin configuration until ~500 years ago when it readvanced into lake catchments at both sites. At our northern site, Sermeq Kujatdleq, the late-Holocene advance of the GrIS approached maximum position during the past 280 years, with the culmination of the advance occurring at AD 1992–1994, and modern retreat was underway by AD 1998–2001. In contrast, field and observational evidence suggest that the ...