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A multi-proxy lacustrine record of Holocene climate change on northeastern Baffin Island, Arctic Canada |
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| Authors: | Jason P Briner Neal Michelutti Donna R Francis Gifford H Miller Yarrow Axford Matthew J Wooller Alexander P Wolfe |
| Institution: | a Geology Department, University at Buffalo, Buffalo, NY 14260, USA b Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, USA c Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA d Department of Geological Sciences and the Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80303, USA e Alaska Stable Isotope Facility, Water and Environmental Research Center and School of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, AL 99775-5860, USA |
| Abstract: | Reconstructions of past environmental changes are critical for understanding the natural variability of Earth's climate system and for providing a context for present and future global change. Radiocarbon-dated lake sediments from Lake CF3, northeastern Baffin Island, Arctic Canada, are used to reconstruct past environmental conditions over the last 11,200 years. Numerous proxies, including chironomid-inferred July air temperatures, diatom-inferred lakewater pH, and sediment organic matter, reveal a pronounced Holocene thermal maximum as much as 5°C warmer than historic summer temperatures from  10,000 to 8500 cal yr B.P. Following rapid cooling 8500 cal yr B.P., Lake CF3 proxies indicate cooling through the late Holocene. At many sites in northeastern Canada, the Holocene thermal maximum occurred later than at Lake CF3; this late onset of Holocene warmth is generally attributed to the impacts of the decaying Laurentide Ice Sheet on early Holocene temperatures in northeastern Canada. However, the lacustrine proxies in Lake CF3 apparently responded to insolation-driven warmth, despite the proximity of Lake CF3 to the Laurentide Ice Sheet and its meltwater. The magnitude and timing of the Holocene thermal maximum at Lake CF3 indicate that temperatures and environmental conditions at this site are highly sensitive to changes in radiative forcing. |
| Keywords: | Climate change Arctic Lacustrine record Holocene thermal maximum Chironomid Diatom Organic matter |
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