A "deep" ice core from east Greenland

Författare

Sigfus J. Johnsen
Henrik B. Clausen
Willi Dansgaard
Niels S. Gundestrup
Margareta Hansson
Peter Jonsson
Jørgen P. Steffensen
Arny E. Sveinbjörnsdottir

Summary, in English

Pilot studies on the Renland peninsula in Scoresbysund Fjord, East Greenland, indicated that the relatively small and separate Renland ice cap meets most of the criteria defining a favourable ice-core drill-site. In 1988, a Nordic expedition recovered a continuous surface-to-bedrock ice core from the summit. This relatively short core reaches deep into the past, probably throughout the last glaciation and through most of the preceding interglacial, Eem, 125,000 years B.P. The core contains detailed information on temporal changes of the coastal environment, and serves as a valuable complement to the new deep ice cores being drilled in Central Greenland. Core analyses suggest that (1) during Eemian time the East Greenland climate was at least 5ÔC warmer than now, and the precipitation 20% higher; (2) during the last glacial period, the precipitation decreased to a minimum, perhaps only 20% of the present value; (3) the post-glacial climatic optimum was 2,5ÔC warmer than now; (4) the long-term variability of the record is relatively low, due to isostatic movements in the area; and (5) from 70,000 years B.P. the Greenland glacial climate alternated between two quasi-stable stages. The latter point may reflect a chaotic feature of climate. If so, climate predictions will be difficult to access.

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