Campus Units

Geological and Atmospheric Sciences

Document Type

Article

Publication Version

Published Version

Publication Date

3-18-2006

Journal or Book Title

Journal of Geophysical Research: Earth Surface

Volume

111

Issue

F1

DOI

10.1029/2005JF000359

Abstract

In most models of glacial erosion, glacier sliding velocity is hypothesized to control rates of bedrock erosion. If this hypothesis is correct, then the elevation difference between hanging and trunk valley floors, the hang height, should be dictated by the relative sliding velocities of the glaciers that occupied these valleys. By considering sliding velocity to be proportional to balance velocity and using mass continuity, hang height is expressed in terms of glacier catchment areas, slopes, and widths, which can be estimated for past glaciers from the morphology of glacial valleys. These parameters were estimated for 46 hanging valleys and their trunk valleys in three adjacent regions of Jasper National Park. The variability in valley morphology can account for 55–85% of the hang height variability if erosion rate scales with balance velocity raised to a power of 1/3. This correspondence is in spite of spatial variations in glaciation duration, snow accumulation rates, and other variables that likely affected hang heights but cannot be readily estimated and so are not included in our formulation. Thus it appears that balance velocity, and by extension, sliding velocity if the two are proportional, may be a reasonable control variable for assessing erosion rate.

Comments

This article is from Journal of Geophysical Research: Earth Surface 111 (2006): F01020, doi:10.1029/2005JF000359. Posted with permission.

Copyright Owner

American Geophysical Union

Language

en

File Format

application/pdf

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