The Ice-Rock Interface and Basal Sliding Process as Revealed by Direct Observation in Bore Holes and Tunnels

Abstract The glacier bed, where basal sliding occurs, was reached by cable-tool drilling and sand-pump bailing in seven bore holes in Blue Glacier, Olympic National Park, Washington. Basal sliding velocities measured by bore-hole photography and confirmed by inclinometry are unexpectedly low, rangin...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Kamb, B., Engelhardt, H. F., Harrison, W. D.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1979
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000030124
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030124
Description
Summary:Abstract The glacier bed, where basal sliding occurs, was reached by cable-tool drilling and sand-pump bailing in seven bore holes in Blue Glacier, Olympic National Park, Washington. Basal sliding velocities measured by bore-hole photography and confirmed by inclinometry are unexpectedly low, ranging from 0.3 to 3.0 cm/day and averaging 1.0 cm/day. This is much less than about half the surface velocity of 15 cm/day, which was the sliding-rate expected from earlier deformation measurements in bore holes made by thermal drilling alone.