SCIENCE@home

Effects of Ice Deformation on Röthlisberger Channels and Implications for Transitions in Subglacial Hydrology

C. Meyer,Matheus C. Fernandes,T. Creyts,J. Rice

Published 2016 in Journal of Glaciology

ABSTRACT

Along the base of glaciers and ice sheets, the sliding of ice over till depends critically on water drainage. In locations where drainage occurs through Rothlisberger channels, the effective pres- sure along the base of the ice increases and can lead to a strengthening of the bed, which reduces glacier sliding. The formation of Rothlisberger channels depends on two competing effects: (1) melting from tur- bulent dissipation opens the channel walls and (2) creep flow driven by the weight of the overlying ice closes the channels radially inward. Variation in downstream ice velocity along the channel axis, re- ferred to as an antiplane shear strain rate, decreases the effective viscosity. The softening of the ice increases creep closure velocities. In this way, even a modest addition of antiplane shear can double the size of the Rothlisberger channels for a fixed water pressure or allow channels of a fixed radius to operate at lower effective pressure, potentially decreasing the strength of the surrounding bed. Furthermore, we show that Rothlisberger channels can be deformed away from a circular cross section under applied antiplane shear. These results can have broad impacts on sliding velocities and po- tentially affect the total ice flux out of glaciers and ice streams.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-99 of 99 references · Page 1 of 1

CITED BY

Showing 1-41 of 41 citing papers · Page 1 of 1