xxi
Fig. 5 Topographic map of Schirmacher Oasis with contour lines
of Polar ice sheet to the south of it along with spot heights
of different places in and around the Schirmacher Oasis.
The yellow dashed rectangular box inserted in the map
is the study area, where detail investigation was carried out.
(Source: Topographic map of the Schirmacher Oasis
(1:25000) published in Leningrad, USSR (1972),
on the basis of aerial photographs taken in 1961) ............................. 129
Fig. 6 (a) Elevation map showing gradually lowering of the Polar
ice sheet from southwest to northeast of the study area plotted
over the Toposheet. (b) Surface slope map of the Polar ice sheet
in the study area showing a large flat area towards south
and the steep slope towards the northern part, which is plotted
over the Toposheet. (c) Ice thickness map of the Polar ice sheet
in the study area plotted over the Toposheet showing an overall
increase in the thickness from north towards south. The area
lying close to the Schirmacher Oasis – Polar ice sheet margin
(SOPIM) has less ice thickness, but the area is very less as
compared to its southern continuation where the thickness
of the ice increases abruptly. (d) Bed elevation map of the
Polar ice sheet in the study area plotted over the Toposheet
showing an overall increase in the elevation of the bedrock
from northeast to southwest. The area lying close to the
Schirmacher Oasis – Polar ice sheet margin (SOPIM) has
bedrock elevation less than 100 m amsl, while that towards
southwestern part has the highest bedrock elevation
of 384 m amsl. (e) Bedrock slope map of the Polar ice
sheet in the study area plotted over the Toposheet showing
an overall increase in the bedrock slope from northeast
to southwest. The area lying close to the SOPIM is virtually
flat with less than 2° slope, whereas that towards the
southwestern part of the study area has the steepest slope
“of 12.6°. (f) Stress map of the Polar ice sheet in the study
area plotted over the Toposheet showing a large area under
less stress zone upto 53 mPa. However, a linear zone
of a moderate stress is located towards the north-central
part of the study area. A small area towards the southwestern
part of the study area and lying close to the Veteheia nunatak
shows a zone of moderate stress of about 100 kPa ............................ 130
Fig. 7 Crevasse map of the Polar ice sheet to the south of the
Schirmacher Oasis showing orientation and population
of the crevasses. Snow cover on the Polar ice sheet are
marked by white coloured patches..................................................... 132
Fig. 8 (a) Model 1 showing the scenario which will happen during
a cooling phase. Note the increase in the surface slope θ due
List of Figures
Fig. 5 Topographic map of Schirmacher Oasis with contour lines
of Polar ice sheet to the south of it along with spot heights
of different places in and around the Schirmacher Oasis.
The yellow dashed rectangular box inserted in the map
is the study area, where detail investigation was carried out.
(Source: Topographic map of the Schirmacher Oasis
(1:25000) published in Leningrad, USSR (1972),
on the basis of aerial photographs taken in 1961) ............................. 129
Fig. 6 (a) Elevation map showing gradually lowering of the Polar
ice sheet from southwest to northeast of the study area plotted
over the Toposheet. (b) Surface slope map of the Polar ice sheet
in the study area showing a large flat area towards south
and the steep slope towards the northern part, which is plotted
over the Toposheet. (c) Ice thickness map of the Polar ice sheet
in the study area plotted over the Toposheet showing an overall
increase in the thickness from north towards south. The area
lying close to the Schirmacher Oasis – Polar ice sheet margin
(SOPIM) has less ice thickness, but the area is very less as
compared to its southern continuation where the thickness
of the ice increases abruptly. (d) Bed elevation map of the
Polar ice sheet in the study area plotted over the Toposheet
showing an overall increase in the elevation of the bedrock
from northeast to southwest. The area lying close to the
Schirmacher Oasis – Polar ice sheet margin (SOPIM) has
bedrock elevation less than 100 m amsl, while that towards
southwestern part has the highest bedrock elevation
of 384 m amsl. (e) Bedrock slope map of the Polar ice
sheet in the study area plotted over the Toposheet showing
an overall increase in the bedrock slope from northeast
to southwest. The area lying close to the SOPIM is virtually
flat with less than 2° slope, whereas that towards the
southwestern part of the study area has the steepest slope
“of 12.6°. (f) Stress map of the Polar ice sheet in the study
area plotted over the Toposheet showing a large area under
less stress zone upto 53 mPa. However, a linear zone
of a moderate stress is located towards the north-central
part of the study area. A small area towards the southwestern
part of the study area and lying close to the Veteheia nunatak
shows a zone of moderate stress of about 100 kPa ............................ 130
Fig. 7 Crevasse map of the Polar ice sheet to the south of the
Schirmacher Oasis showing orientation and population
of the crevasses. Snow cover on the Polar ice sheet are
marked by white coloured patches..................................................... 132
Fig. 8 (a) Model 1 showing the scenario which will happen during
a cooling phase. Note the increase in the surface slope θ due
List of Figures