Morphological Characteristics of the Ice Margins of Antarctic Ice Shelf and Outlet Glacier Extracted from ICESat Laser Altimetry Along-Track Profiles

  • Author(s): Jieun Kim, Jaehyung Yu, Lei Wang, Hongxing Liu, and Haein Shin
  • DOI: 10.3319/TAO.2015.12.24.01(ISRS)
  • Keywords: Morphological characteristic, Laser altimetry profile, Bottom-up segmentation algorithm
Abstract

The Antarctic ice sheet topography including elevation and slope is a key parameter for understanding ice sheet dynamics because the surface slope is a major controller of the ice flow gravitational driving stress magnitude. This study used Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry data to analyze the ice margin morphological parameters for 20 ice shelves and 12 outlet glaciers distributed over Antarctica. The bottom-up segmentation algorithm application effectively extracted the morphological parameters from the laser altimetry profiles. The ice shelves had an average boundary elevation of 29.5 m and a slope of 7.8°, with a decreasing surface slope pattern from the boundary to the inner side. The average number of segments and the length of the coastal margin for ice shelves extracted from the bottom-up segmentation algorithm is 3.2 and is 18.4 km, respectively. The outlet glaciers had a boundary elevation of 29.7 m with a slope of 7.4°. The average number of segments for outlet glaciers is 5.03, and the distance to the margin is 10.38 km. The outlet glaciers were of two types. The first type had a higher ice margin slope, a shorter ice margin distance and concave shape to the surface profile. The second type had a much shorter ice margin distance and an undulating surface profile shape. The ice margin morphology shows distinctive characteristics depending on the major ice loss process.

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