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Development of supraglacial drainage systems on the Devon Ice Cap and its connection to the formation of near-surface ice layers within the shallow firn

  • Author / Creator
    Fernandes, Luisa DC
  • Increased mass loss from the Canadian Arctic ice caps is associated with regional increases in the summer mean glacier surface temperature and the annual number of melt days. As a result of these changes , snow and ice melt are likely to occur at higher elevations and become more widespread, especially in the percolation zone, where surface meltwater percolates into the subsurface and refreezes. Such a process adds uncertainties to predictions of rates of both glacier mass loss and ensuing sea-level rise because of the unknown distribution of locations at which meltwater percolates and refreezes. The absence of a known infiltration pattern makes it challenging to obtain accurate information about all the processes associated with firn densification and its impact on the development of supraglacial drainage networks. This study used remote sensing techniques to identify permeable and impermeable substrates within the accumulation zone of the Devon Ice Cap by mapping temporal changes in the extent and distribution of glacier facies zones and inter-annual variability in the spatial extent, timing and characteristics of supraglacial meltwater runoff. Comparisons between observations obtained from satellite remote sensing data and ground-truth data obtained using Ground Penetrating Radar and shallow firn cores are used to ascertain whether the methods used facilitate the study of changes in firn structure over large geographical areas. Our results suggest that analysis of the distribution and inter-annual variability of supraglacial drainage networks in firn-covered regions is a promising approach to study regional scale changes in firn structure at a relatively low cost, and to characterize spatial heterogeneity in firn runoff processes that contribute to glacier mass loss and, ultimately, sea-level rise.

  • Subjects / Keywords
  • Graduation date
    Spring 2021
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/r3-vfwk-8469
  • 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.