16
First-Year Ice
Multiyear Ice
S B = 14.237 0.194TF
12
8
S B = 7.879 0.016TF
4
Figure 11. Sea-ice bulk salinity vs.
floe thickness (after Cox and Weeks
0
100
200
300
400
1974).
TF, Floe Thickness (cm)
kov 5/4
4
3
2
σ C (T-F) = 0.621 + 0.855 σC (Ex)
1
r 2 = 0.942
Figure 12. Timco and Frederking esti-
mated full ice sheet horizontal uncon-
fined compressive strength vs. Exxon's
0
1
2
3
4
σC ( Ex) , Exxon's Horizontal Unconfined Compressive Strength (MPa)
field-measured values.
reveals the interrelationship of average ice sheet
and Frederking. However, the modified method
for determining σc gives values that are still offset
temperature and bulk salinity with the bulk po-
rosity.
from the Exxon field test results (Fig. 15). To alle-
Using the SB values determined from eq 2, the
viate this offset, eq 5 was revised to read
average ice floe temperature listed in Table 3, and
the equation provided in Figure 13, φB was esti-
(
)
σc = 37 ε0.22 1 - φ B.93/ 270
0.5
0
- 0.65 .
˙
(8)
mated for each of the Exxon ice sheets. These νB,
SB, and φB values are listed in Table 3 as the right
This revision brings the σc values (Table 3) into
column under each respective heading. Using the
new φB values and the related strain rates in Table
better agreement with the field determinations,
3, σc was recalculated using eq 5. These so-called
as shown in Figure 16.
modified σc values were then compared (Fig. 14)
If the DC conductivity of the ice could be de-
with the σ c estimates made by Timco and
termined remotely along with ice sheet thickness,
then SB could be determined from eq 2 and νB
Frederking (Table 3). As can be seen in Figure 14,
using the above φB estimates in eq 5 gives σc
estimated from an expression similar to that given
in Figure 6 and φB from Figure 17. The data in
values that are comparable with those of Timco
8
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