Modelling Laurentide ice stream thermomechanics ...

• Main Author: Marshall, Shawn Joseph
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Ice Sheet
• Online Access: https://dx.doi.org/10.14288/1.0053153; https://doi.library.ubc.ca/10.14288/1.0053153

Ice streams are fast-flow currents which represent a small areal fraction in an ice sheet but account for the majority of ice sheet drainage. Because ice streams are inherently complex and are subgrid in current numerical models, they have not been portrayed in large-scale ice sheet studies. I employ a continuum mixture framework to incorporate ice streams in a three-dimensional thermomechanical model of the Laurentide Ice Sheet. The ice mass is composed of a binary mixture of sheet ice, which flows by viscous creep deformation, and stream ice, which flows by decoupled sliding and/or sediment deformation at the bed. Dynamic and thermal evolutions are solved for each component in the mixture, with coupling rules to govern transfer between flow regimes. These transfers represent the activation, growth, and deactivation of ice streams, manifest by creep exchange and bed exchange of ice. I express the governing equations for mass, momentum, and energy balance in a form suitable for direct incorporation in ...