Quantifying the character and short-term evolution of blue-ice moraines, Heritage Range, Antarctica: Integration and comparison of repeat UAV, TLS and dGPS-derived datasets

Abstract:

Blue-ice moraines are associated with katabatic winds that enhance ablation and sublimation at the base of nunataks which create surface depressions that are compensated for by ice-flow from an adjacent trunk glacier, and at right-angles to the main flow direction. It is hypothesised that this flow regime transports basal debris which emerges glacier surface at the base of the nunatak, where it resides for long periods of time. Quantifying the long- and short-term evolution and persistence of these features is central to refining estimates of, and constraining the principles drivers of long-term ice-sheet stability. High resolution digital elevation models derived from sUAV photography and Structure-from-Motion (SfM) photogrammetry, and Terrestrial Laser Scanning have been used to quantify rates and patterns of topographic change across a blue-ice moraine in the Heritage Range, West Antarctica, between the 2012/13 and 2013/14 melt seasons, and within the 2012/13 melt season. We benchmark these SfM-TLS derived change detection data against coincident dGPS ablation and movement stake data, with a view to assessing the utility of the different approaches for resolving small-scale (centimetric to sub-centimetric) surface change in ice-marginal areas over annual and sub-annual timescales.