Geology Reference
In-Depth Information
shown earlier in Figure 5.6. During the first study period
1-27 October 1981, the new ice cover grew from 0.24 to
0.54 m in thickness.
As can be seen in Figure 5.8, the ice cover had reached a
maximum thickness of 2.25 m and a snow cover depth of
0.65 m. By the end of the major growth season significant
differences developed in the thickness of snow and ice
across the bay as can be seen in Figure 5.9. The difference
in the thickness of snow cover was the primary factor that
governed the growth in ice. There was very little snow, less
than 10 mm, at station 8 near the western shore of the fjord
(see identifications of various stations in Figures 5.4 and
5.5) during the main part of the growing period (about 220
days). Consequently, the ice at this site was relatively thicker
than that at other locations. The ice remained intact for a
slightly longer period at this site probably because the ice at
this location was colder due to the lower snow accumula-
tion. Moreover, the western shoreline was very steep and
the water depth at this site was also the greatest (210 m)
causing probably the least tidal wave and wind‐ related
effects. On the onset of melting, however, snow cover
retarded the rate of melting in areas covered with thicker
snow cover. Once the snow at this site melted, the ice
around this location and near the western shoreline started
to melt rapidly due to the decrease in albedo and higher
absorption of solar radiation (even from diffused sun).
Snow, aes
2.5
Ice, aes
Ice, 1
Snow, 1
2
Ice, 2
Snow, 2
Ice
Ice, 3
Snow, 3
1. 5
Ice, 4
Snow, 4
Large crack
between
station 4 & 6
Ice, 5
1
Snow, 5
Ice, 6
Snow, 6
Snow
Ice, 7
0.5
Snow, 7
Ice, 8
Snow, 8
0
0
50 100
Growing days: 24 Sept. 1981 to 13 June 1982
150
200
250
300
Figure 5.8
Growth in sea ice and snow cover at various sites along the 7.2 km long experimental line across
Mould Bay, up to 13 June 1982, as functions of number of days after the freezing started on 24 September 1981;
large crack crossing the experimental line developed a few days before 29 May 1982 (N. K. Sinha, unpublished).
(a)
(b)
0.7
2.5
4 June, 1982
0.6
2
13 June, 1982
0.5
13 June, 1982
4 June, 1982
1. 5
0.4
0.3
1 Jan, 1982
1
1 Jan, 1982
0.2
31 Oct, 1981
0.5
0.1
31 Oct, 1981
0
0
0
1
2 3
Distance across mould bay, km
4
5
6
7
8
0
1
2 3
Distance across mould bay, km
4
5
6
7
8
Figure 5.9
(a) Snow and (b) ice thickness across the bay during the winter of 1981-1982 and up to 13 June 1982
just before the start of rapid melting (N. K. Sinha, unpublished).
