Characterization and interpretation of polythermal structure in two subarctic glaciers

Author: 
Date created: 
2012-11-29
Identifier: 
etd7550
Keywords: 
Glacier
Polythermal
Radar
Model
Kluane
Climate
Abstract: 

I use ice-penetrating radar to probe the thermal structure in two small glaciers in the Saint Elias Range, southwestern Yukon. I develop processing workflows to separate bed and englacial reflections in radar and use these to build maps of both bed topography and englacial scattering. Comparison with borehole data shows that englacial scattering occurs in ice at the freezing point. The pattern in thermal structure suggests that the observed regime is dominated by accumulation zone processes. I develop a numerical model to simulate steady and time-dependent thermal regimes in glaciers. Diagnostic simulations support the hypothesis that meltwater entrapment is a critical control on the observed structure. Sensitivity tests suggest a climate sensitivity such that thinning and retreat of the near-surface aquifer may dramatically alter the thermal structure. Prognostic simulations illustrate scenarios in which these polythermal glaciers may cool as climate warms in the future.

Document type: 
Thesis
Rights: 
Copyright remains with the author. The author granted permission for the file to be printed and for the text to be copied and pasted.
File(s): 
Supervisor(s): 
Gwenn Flowers
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.
Statistics: