| PALEOLIMNOLOGY |
Recent Warming in a 500-Year Paleotemperature Record from Varved Sediments: Upper Soper Lake, Baffin Island, Canada
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Hughen, K.A., J.T. Overpeck, R.F. Anderson. 2000. Recent Warming in a 500-Year Paleotemperature Record from Varved Sediments:
Upper Soper Lake, Baffin Island, Canada. The Holocene Vol. 10, no. 1, pp. 9-19
| Data Coverage |
North: 62.9167 * South: 62.9167 |
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West: -69.8833 * East: -69.8833 |
Start Year: 436 cal yr BP * End Year: -42 cal yr BP
Data: Please Cite Data Contributors!
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Summary: Laminated sediments from Upper Soper Lake on southern Baffin Island provide a new 500-year record of temperature change in
the Arctic. Radiometric dating, using 210 Pb and Pu, shows that the light- and dark-coloured laminae couplets are annually
deposited varves. Dark laminae thickness is strongly correlated to average June temperature from Kimmirut (r = 0.82), reflecting
the influence of temperature on snowmelt and fluxes of runoff and suspended sediment. This relationship allowed the construction
of a palaeotemperature record that documents large-amplitude interannual to decadal variability superimposed on distinct
century-scale trends, including 2°C average warming and maximum temperatures during the 1900s. Similar patterns of change
are seen in individual and regionally averaged palaeotemperature records from around the circum-Arctic. Upper Soper Lake
records temperatures, rates of change and variance during the twentieth century that are all anomalously high within the
context of the last 500 years, and outside the observed range of natural variability. Comparisons of Upper Soper Lake and
Arctic average palaeotemperature to proxy-records of hypothesized forcing mechanisms suggest that the recent warming trend
is mostly due to anthropogenic emissions of atmospheric greenhouse gases. The magnitude of the warming and decade-scale
variability throughout the records, however, indicate that natural forcing mechanisms such as changing solar irradiance and
volcanic activity, as well as positive feedbacks within the Arctic environment, also play an important role.
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Complete XML Record: noaa-lake-5465
(Last Revised: 2007-09-05 )
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