The Effect of Glacial Cross-Section on Vertical Resistivity Depth Soundings

The determination of glacial ice thickness by vertical resistivity depth soundings relies upon the use of theoretical curves which neglect the effect of valley walls. To improve the utility of glacial resistivity measurements an analytical expression is derived for the apparent resistivity determine...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Taylor, R. W., Greenfield, R. J.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1973
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000031798
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031798
Description
Summary:The determination of glacial ice thickness by vertical resistivity depth soundings relies upon the use of theoretical curves which neglect the effect of valley walls. To improve the utility of glacial resistivity measurements an analytical expression is derived for the apparent resistivity determined by a Wenner array oriented parallel to the strike of a layered trough embedded in a perfectly conducting half space. Numerical evaluation of this expression allows the effects of glacial cross-section to be determined. It is shown that the presence of valley walls and layering within the glacier can strongly effect the determination of total ice thickness, and a criterion for the reliable use of plane-layered master curves in the interpretation of field data is established. An apparent resistivity curve calculated for a layered trough is shown to give an excellent fit to field data published by Röthlisberger and Vögtli (1967).