A Model of Basal Hydrologic Networks and Effective Stress Beneath an Ice Sheet
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Date
2012
Authors
Papamarcos, Sara
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
Subglacial processes that control the water pressure and flow determine the large-scale
behavior of the overlying ice by regulating basal resistance. We implement a
model in which a steady-state subglacial conduit system is surrounded by fully saturated
porous media. We investigate branching in this system at fixed angles
of 15 degrees, 30 degrees
and 45 degrees
to the direction of ice flow and further assess these systems by
calculating the hydraulic potential gradient to determine conduit flow path. We
solve our governing equations for porous media flow and allow ice infiltration of
the pore space to occur at a critical effective stress N infiltration. For low values of
N infiltration, ice infiltration of sediment allows these conduits to follow their original
paths. Where insufficient ice infiltration occurs, the conduit path instead lies
parallel to the direction of ice flow. Our results speak to the importance of
incorporating small-scale processes into models of subglacial hydrologic networks.
Description
Keywords
Basal, Conduit, Effective stress, Hydrology, Porous media flow, Subglacial