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The spatial structure and temporal development of supraglacial drainage systems, and their influence on the flow dynamics of High Arctic ice caps

  • Author / Creator
    Wyatt, Faye R
  • The Canadian Arctic Archipelago (CAA) contains 1/3 of global glaciers and ice caps by area. Recent increases in mean summer air temperature have resulted in increased mass loss from these glaciers, which have become the largest regional contributor to eustatic sea level rise after the continental ice sheets. Increases in glacier velocity triggered by `hydrological forcing' can increase the transfer of ice from high to low elevations, accelerating mass loss. Hydrological forcing requires surface meltwater to reach the glacier bed, where it reduces basal friction and increases basal sliding and glacier velocities. However the role of supraglacial meltwater drainage processes in creating hydrological forcing is poorly understood. This study characterizes the supraglacial drainage system of a large ice cap in the CAA, and explores how it controls the delivery of water to the ice cap bed, and how this is reflected in the flow of the ice cap. Annual mean velocities of outlet glaciers draining the Devon Ice Cap (DIC) vary significantly from year to year. The highest variability is observed where surface meltwater penetrates to the glacier bed and in regions where basal sliding contributes to glacier velocities. This suggests that hydrological forcing is occurring in some regions of the DIC. This study finds that there are differences in the structure and distribution of supraglacial drainage systems where basal sliding occurs, which affects the volume, distribution and rate of meltwater delivery to glacier bed. A feedback may exist between supraglacial drainage and ice dynamics, as the structure of the drainage system delivers larger and more variable amounts of surface meltwater to a wider area of the glacier bed where basal sliding occurs, which may increase the sensitivity of these regions to climate warming. Exploring how the structure and distribution of surface drainage features and the delivery of surface meltwater to the bed vary across an ice cap, and how this may change as climate warms, enhances our understanding of the dynamic behaviour of glaciers and ice caps in the CAA.

  • Subjects / Keywords
  • Graduation date
    2013-11
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/R37H1DZ1K
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
    English
  • Institution
    University of Alberta
  • Degree level
    Doctoral
  • Department
    • Department of Earth and Atmospheric Sciences
  • Supervisor / co-supervisor and their department(s)
    • Sharp, Martin (Earth and Atmospheric Sciences)
  • Examining committee members and their departments
    • Sarah Das (Woods Hole Oceanographic Institution)
    • Jeff Kavanaugh (Earth and Atmospheric Sciences)
    • Arturo Sanchez (Earth and Atmospheric Sciences)
    • Uldis Silins (Renewable Resources)