123
two distinct types of contact. Towards the westernmost part, the Schirmacher
Oasis – Polar ice sheet margin (SOPIM) is sharp, where 20–30 m thick ice wall is
seen. This is named as the Western Wall. A large tract of the eastern Schirmacher
lying to the south of Maitri and Novolazarevskaya station shows a thick ice wall
which has been named as the Eastern Wall. The central and a part of the eastern side
of the SOPIM shows a gradual slope from the Polar ice sheet, towards the
Schirmacher Oasis. The recession of the Polar ice sheet around the Schirmacher
Oasis during the austral summer period is a continuous phenomenon, which depends
upon the lithological and thermal characteristics of nearby rocks (Swain 2019).
3 Methodology
3.1 Surface Slope Determination
Under the impending climate change scenario, surface slope forms an important
parameter. Direct interaction of the atmosphere on the snow and ice surfaces determines the energy balance of the region. Predominantly, melt occurs in response to
radiative energy, which may account for >70% of the net energy (Hock 2005).
Impurities at the ice/atmosphere interface contribute to the development of surface
roughness at metre to sub-metre scales. Glacier roughness at sub-metre scales is an
important control on the ice surface energy balance and has implications for scattering energy measured by remote-sensing instruments. Ice surface roughness is
dynamic as a consequence of spatial and temporal variation in ablation. Studies
relying on singular and/or spatially discrete two-dimensional profiles to describe ice
surface roughness have a limitation to resolve common patterns or causes of variation in glacier surface morphology. Though the attempts were made using closerange digital photogrammetry as a rapid and cost-effective method to retrieve
three-dimensional data detailing plot-scale supraglacial topography (Irvine-Fynn
et al. 2014) in Midtre Lovénbreen glacier of Arctic Region, the Polar ice sheet south
of the Schirmacher Oasis appears to be smooth and no large scale surface roughness
is visible. Surface slope of the glaciers can also be determined by large scale DEM
of the region, where large scale altitudinal data is available along with highly accurate spatial variable parameters. For most of the southern Polar Region beyond
60°S, Shuttle Radar Topographic Mission (SRTM) dataset, with high resolution is
not available. In this regard, a DEM was prepared with good accuracy for this area
directly from the elevation data based on the contour heights from the published
topographic map (Swain 2015). The contour difference of 10 m was taken into consideration for drawing contour lines and accordingly these values were plotted in
GIS platform to prepare the desired DEM. Also based on these values, spot heights
from the published map were adjusted to that of the contour heights and the geographic coordinates (latitude and longitude) of location were taken into consideration and the values were put into a surfer database. Accordingly surface slope is
determined with high accuracy.
Glacier Stress Pattern as an Indicator for Climate Change
two distinct types of contact. Towards the westernmost part, the Schirmacher
Oasis – Polar ice sheet margin (SOPIM) is sharp, where 20–30 m thick ice wall is
seen. This is named as the Western Wall. A large tract of the eastern Schirmacher
lying to the south of Maitri and Novolazarevskaya station shows a thick ice wall
which has been named as the Eastern Wall. The central and a part of the eastern side
of the SOPIM shows a gradual slope from the Polar ice sheet, towards the
Schirmacher Oasis. The recession of the Polar ice sheet around the Schirmacher
Oasis during the austral summer period is a continuous phenomenon, which depends
upon the lithological and thermal characteristics of nearby rocks (Swain 2019).
3 Methodology
3.1 Surface Slope Determination
Under the impending climate change scenario, surface slope forms an important
parameter. Direct interaction of the atmosphere on the snow and ice surfaces determines the energy balance of the region. Predominantly, melt occurs in response to
radiative energy, which may account for >70% of the net energy (Hock 2005).
Impurities at the ice/atmosphere interface contribute to the development of surface
roughness at metre to sub-metre scales. Glacier roughness at sub-metre scales is an
important control on the ice surface energy balance and has implications for scattering energy measured by remote-sensing instruments. Ice surface roughness is
dynamic as a consequence of spatial and temporal variation in ablation. Studies
relying on singular and/or spatially discrete two-dimensional profiles to describe ice
surface roughness have a limitation to resolve common patterns or causes of variation in glacier surface morphology. Though the attempts were made using closerange digital photogrammetry as a rapid and cost-effective method to retrieve
three-dimensional data detailing plot-scale supraglacial topography (Irvine-Fynn
et al. 2014) in Midtre Lovénbreen glacier of Arctic Region, the Polar ice sheet south
of the Schirmacher Oasis appears to be smooth and no large scale surface roughness
is visible. Surface slope of the glaciers can also be determined by large scale DEM
of the region, where large scale altitudinal data is available along with highly accurate spatial variable parameters. For most of the southern Polar Region beyond
60°S, Shuttle Radar Topographic Mission (SRTM) dataset, with high resolution is
not available. In this regard, a DEM was prepared with good accuracy for this area
directly from the elevation data based on the contour heights from the published
topographic map (Swain 2015). The contour difference of 10 m was taken into consideration for drawing contour lines and accordingly these values were plotted in
GIS platform to prepare the desired DEM. Also based on these values, spot heights
from the published map were adjusted to that of the contour heights and the geographic coordinates (latitude and longitude) of location were taken into consideration and the values were put into a surfer database. Accordingly surface slope is
determined with high accuracy.
Glacier Stress Pattern as an Indicator for Climate Change