The Margin of the Greenland Ice Sheet at Isua

• Published in: Journal of Glaciology
• Main Authors: Colbeck, S. C., Gow, A. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1979
• Subjects: Earth-Surface Processes; Greenland; Ice Sheet; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000014714; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000014714

Abstract Field studies at a particular place at the margin of the Greenland ice sheet have provided information about the ice sheet. Ice temperatures were measured in five drill holes, two of which reached the unfrozen area of basal melting. Surface water entered these two bore holes, reaching the base in one, but remaining 59 m above the base in the other. The existence of this water conduit or fracture at 240 m depth, the calculated temperature profiles, and the local bedrock configuration suggest an area of stationary ice overridden by the ice sheet. This situation suggests creep rupture at depth in the ice sheet. Ice-fabric analysis made above 240 m depth shows patterns similar to fabrics elsewhere near the margin in zones of low deviatoric stress. Unfortunately no cores were obtained below that depth where stationary ice may exist.