Published In

Annals of Glaciology

Document Type

Article

Publication Date

1-1-2011

Subjects

Subglacial lakes -- Antarctica, Aquatic ecology -- Antarctica, Ice sheets -- Antarctica

Abstract

Locations of subglacial lakes discovered under fast-moving West Antarctic ice streams tend to be associated with topographic features of the subglacial bed or with areas that have strong variations in basal conditions. Inversion of ice-stream surface velocity indicates that basal conditions under ice streams can be highly variable and that there can be widespread regions where basal traction is high. To seek an explanation for why lakes appear to be sited near areas with high basal traction, we use numerical models to simulate ice-stream dynamics, thermodynamics and subglacial water flow. We demonstrate that the ice flow over high basal traction areas produces favourable conditions for the ponding of meltwater. Energy dissipation associated with ice sliding over a region with high basal traction constitutes a water source supplying a lake, and ice-thickness perturbations induced by ice flow over variable traction create local minima in hydraulic potential. Variations in thermodynamic processes caused by such ice flow could be responsible for limiting the horizontal extent of the subglacial lakes.

Description

Originally appeared in Annals of Glaciology, published by the International Glaciological Society. Article can be found at http://www.igsoc.org/annals/

DOI

10.3189/172756411797252176

Persistent Identifier

http://archives.pdx.edu/ds/psu/8425

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