The Constitution of Valley Glaciers

Abstract Ice streams composing a compound valley glacier may be juxtaposed, inset or superimposed, and Demorest’s concepts of ice flowage provide a plausible explanation for these relations. If valley floors are accordant, juxtaposition results because the waxing force of gravity and obstructed grav...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Sharp, Robert P.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1948
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000008042
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000008042
Description
Summary:Abstract Ice streams composing a compound valley glacier may be juxtaposed, inset or superimposed, and Demorest’s concepts of ice flowage provide a plausible explanation for these relations. If valley floors are accordant, juxtaposition results because the waxing force of gravity and obstructed gravity flow in the tributary glacier overcomes the waning force of obstructed extrusion flow from the trunk glacier enabling the tributary to force its way into a juxtaposed position with the trunk glacier in the main valley. If discordance in valley floors is less than the thickness of the trunk glacier, an insert position develops by the same mechanism. If the discordance is greater than the thickness of the trunk glacier, superimposition results. Locally, superimposed or inset relations may be established by exceptionally rapid advances, even with accordant valley floors, but any superimposed ice stream shortly becomes inset by sinking into the underlying ice, at least in temperate glaciers.