Melting temperature changes during slip across subglacial cavities drive basal mass exchange

The importance of glacier sliding has motivated a rich literature describing the thermomechanical interactions between ice, liquid water and bed materials. Early recognition of the gradient in melting temperature across small bed obstacles led to focused studies of regelation. An appreciation for th...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Alan W. Rempel, Colin R. Meyer, Kiya L. Riverman
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2022
Subjects:
Online Access:https://doi.org/10.1017/jog.2021.107
https://doaj.org/article/0c58b305d42142138edf1402c97d8821
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Summary:The importance of glacier sliding has motivated a rich literature describing the thermomechanical interactions between ice, liquid water and bed materials. Early recognition of the gradient in melting temperature across small bed obstacles led to focused studies of regelation. An appreciation for the limits on ice deformation rates downstream of larger obstacles highlighted a role for cavitation, which has subsequently gained prominence in descriptions of subglacial drainage. Here, we show that the changes in melting temperature that accompany changes in normal stress along a sliding ice interface near cavities and other macroscopic drainage elements cause appreciable supercooling and basal mass exchange. This provides the basis of a novel formation mechanism for widely observed laminated debris-rich basal ice layers.