Paleoecological evidence for abrupt cold reversals during peak Holocene warmth on Baffin Island, Arctic Canada |
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Authors: | Yarrow Axford Jason P Briner Donna R Francis |
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Institution: | a Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, UCB 450, Boulder, CO, 80309, USA b Department of Geology, University at Buffalo, 876 Natural Sciences Complex, Buffalo, NY, 14260, USA c Department of Geosciences, University of Massachusetts, 233 Morrill Science Center, Amherst, MA, 01003, USA |
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Abstract: | A continuous record of insect (Chironomidae) remains preserved in lake sediments is used to infer temperature changes at a small lake in Arctic Canada through the Holocene. Early Holocene summers at the study site were characterized by more thermophilous assemblages and warmer inferred temperatures than today, presumably in response to the positive anomaly in Northern Hemisphere summer insolation. Peak early Holocene warmth was interrupted by two cold reversals between 9.5 and 8 cal ka BP, during which multiple cold-stenothermous chironomid taxa appeared in the lake. The earlier reversal appears to correlate with widespread climate anomalies around 9.2 cal ka BP; the age of the younger reversal is equivocal but it may correlate with the 8.2 cal ka BP cold event documented elsewhere. Widespread, abrupt climate shifts in the early Holocene illustrate the susceptibility of the climate system to perturbations, even during periods of enhanced warmth in the Northern Hemisphere. |
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Keywords: | Chironomidae Holocene Arctic Midges Paleoclimate Paleolimnology Abrupt climate change |
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