Geology Reference
In-Depth Information
and a number of melting scenarios may develop again.
The processes of partial melting and freezing may con-
tinue for many seasons.
The usual practice of identifying the age of an ice floe
in moving pack ice is by no means simple. In most cases,
it is not more than wild guesswork, and the quality of
results depends on the field experience of the observer
and convincing arguments he/she presents. Often the
results are erroneous. The only certain method of deter-
mining the age of a relatively flat floe is to obtain
through‐thickness ice cores and examine the vertical
profile of the microstructure by thin sectioning. The pro-
cess is tedious and extremely time consuming. For this rea-
son and to avoid complications and conflicts, sea ice floes
older than 1GS or FY ice are recognized as MY ice for
remote sensing purposes.
The characteristics of the development of shore‐fast
FY ice in Eclipse Sound near the settlement of Pond Inlet
(lat. 72.7°N., long. 78.0°W) in Baffin Island (Figure 5.1a)
were examined extensively with
on‐sight
measurements,
year after year, for almost 10 years during the period
1976-1986 (
Sinha and Nakawo
, 1981;
Nakawo and Sinha
,
1981, 1984;
Sinha
, 1983a, 1983b). The ice in Eclipse
Sound, however, never survived beyond the first melting
season. Consequently, information on the decaying pro-
cesses during the spring and melting of ice covers during
the summer were not investigated in detail. Moreover, no
remote sensing observations were carried out for the ice
in Eclipse Sound. To our knowledge, no systematic long‐
term observations in conjunctions with remote sensing
studies have been carried out for examining the aging
processes of sea ice in the High Arctic until the Mould
Bay experiments that began in 1981. Naturally, the pri-
mary goals of the Mould Bay programs were to quantify
physical characteristics of ice, including strength and
deformation, together with microwave backscatter and
emission coefficients of sea ice during the annual growth,
summer melt, and the major periods of transition as the
ice cover aged from FY ice to My ice. The material in this
section is related to the aging of ice and has been devel-
oped from direct observations carried out at Mould Bay
for four freezing/melting seasons during 1981-1985.
Mould Bay, a 30 km long and 7-9 km wide deep water
(about 200 m) inlet is located in Prince Patrick Island of
the Canadian Archipelago in the Northwest Territories,
Canada, in the western Arctic (Figure 5.1a, 5.1b). The
goals of the Mould Bay programs were to quantify
physical characteristics of ice together with microwave
backscatter and emission coefficients of sea during the
annual growth and major periods of transition as the ice
cover aged. The material in this section has been devel-
oped from the experience of direct observations carried
(a)
(b)
-124°
-116°
-122°
-118°
-120°
Cape Leopold
M'Chntock
Arctic
N
Satellite
Bay
Hobson's
Ice Island
Pr ince
Eureka
77°
77°
Ocean
Patrick
Mould Bay
Island
Resolute
Lands End
Pond Inlet
Mould
Bay
Melville
Qozier
76°
76°
Cape
Manning
Kellett
Eglinton
Island
Channel
Island
Yellow Knife
McClure
Strait
Strait
-124°
-116°
-122°
-118°
-120°
km
0
50
100
Figure 5.1
Map of Canada showing (a) three High‐Arctic long‐term sea ice experimental sites—Hobsons Choice
ice island (≈79°23.5
′
N, 102°20.2
′
W), Mould Bay (76°14
′
N, 119°20
′
W), and Pond Inlet (72°42
′
N, 77°57
′
W) and
(b) details of Prince Patrick Island viewing Mould Bay where Environment Canada operated a weather station
from 1948 to 1997 (N. K. Sinha and M. Shokr, unpublished).
