EGU2020-12364
https://doi.org/10.5194/egusphere-egu2020-12364
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

A slip law for glaciers on deformable beds

Lucas Zoet1 and Neal Iverson2
Lucas Zoet and Neal Iverson
  • 1University of Wisconsin - Madison, Madison, United States of America (lzoet@wisc.edu)
  • 2Iowa State University, Ames, United States of America (niverson@iastate.edu)

Slip of marine-terminating ice streams over beds of deformable till is responsible for most of the contribution of the West Antarctic Ice Sheet to sea-level rise. Flow models of the ice sheet and till-bedded glaciers elsewhere require a law that relates slip resistance, slip velocity, and water pressure at the bed. We present results of the first experiments in which pressurized ice at its melting temperature is slid of over a water-saturated till bed. Steady-state slip resistance increases with slip velocity owing to sliding of ice across the bed, but above a threshold velocity till shears at its rate-independent, Coulomb strength. These results motivate a generalized slip law for glacier-flow models that combines processes of hard-bedded sliding and bed deformation.

How to cite: Zoet, L. and Iverson, N.: A slip law for glaciers on deformable beds, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12364, https://doi.org/10.5194/egusphere-egu2020-12364, 2020

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