Devon Island Ice Cap: Core Stratigraphy and Paleoclimate

  • R. M. Koerner
    Research scientist with the Polar Continental Shelf Project of the Department of Energy, Mines and Resources, Ottawa, Ontario K1A 0E4 Canada

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  • The Canadian Arctic ice caps continue to lose mass in response to the unusual warmth of the past 100 years.

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<jats:p>Valuable paleoclimatic information can be gained by studying the distribution of melt layers in deep ice cores. A profile representing the percentage of ice in melt layers in a core drilled from the Devon Island ice cap plotted against both time and depth shows that the ice cap has experienced a period of very warm summers since 1925, following a period of colder summers between about 1600 and 1925. The earlier period was coldest between 1680 and 1730. There is a high correlation between the melt-layer ice percentage and the mass balance of the ice cap. The relation between them suggests that the ice cap mass balance was zero (accumulation equaled ablation) during the colder period but is negative in the present warmer one. There is no firm evidence of a present cooling trend in the summer conditions on the ice cap. A comparison with the melt-layer ice percentage in cores from the other major Canadian Arctic ice caps shows that the variation of summer conditions found for the Devon Island ice cap is representative for all the large ice caps for about 90 percent of the time. There is also a good correlation between melt-layer percentage and summer sea-ice conditions in the archipelago. This suggests that the search for the northwest passage was influenced by changing climate, with the 19th-century peak of the often tragic exploration coinciding with a period of very cold summers.</jats:p>

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  • Science

    Science 196 (4285), 15-18, 1977-04

    American Association for the Advancement of Science (AAAS)

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