High-resolution proglacial lake records of pre-Little Ice Age glacier advance, northeast Greenland

Adamson, Kathryn, Lane, Timothy, Carney, Matthew, Bishop, Thomas and Delaney, Catherine (2019) High-resolution proglacial lake records of pre-Little Ice Age glacier advance, northeast Greenland. Boreas, 48 (3). pp. 535-550. ISSN 0300-9483

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Abstract

Understanding Arctic glacier sensitivity is key to predicting future response to air temperature rise. Previous studies have used proglacial lake sediment records to reconstruct Holocene glacier advance–retreat patterns in South and West Greenland, but high-resolution glacier records from High Arctic Greenland are scarce, despite the sensitivity of this region to future climate change. Detailed geochemical analysis of proglacial lake sediments close to Zackenberg, northeast Greenland, provides the first high-resolution record of Late Holocene High Arctic glacier behaviour. Three phases of glacier advance have occurred in the last 2000 years. The first two phases (c. 1320–800 cal. a BP) occurred prior to the Little Ice Age (LIA), and correspond to the Dark Ages Cold Period and the Medieval Climate Anomaly. The third phase (c. 700 cal. a BP), representing a smaller scale glacier oscillation, is associated with the onset of the LIA. Our results are consistent with recent evidence of pre-LIA glacier advance in other parts of the Arctic, including South andWest Greenland, Svalbard, and Canada. The sub-millennial glacier fluctuations identified in the Madsen Lake succession are not preserved in the moraine record. Importantly, coupledXRFandXRDanalysis has effectively identified a phase of ice advance that is not visible bysedimentology alone. This highlights the value of high-resolution geochemical analysis of lake sediments to establish rapid glacier advance–retreat patterns in regions where chronological and morphostratigraphical control is limited.