Geology Reference
In-Depth Information
(A)
3.35
2.52
Ice
Frozen
saturated peat
1.68
0.84
Water
Unfrozen saturated peat
Dry peat
Insulators
0
0
100%
75%
50%
25%
0
Porosity
(B)
W m/°C
1
2.5
2
4
1.5
0.5
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
Temperature °C
Figure 5.2.
Thermal and physical properties of sand and clay when subject to freezing and thawing
temperatures. (A) Relationship between thermal conductivity, porosity, and degree of saturation.
From Johnston (1981). (B) Temperature dependence of thermal conductivity of materials of differ-
ent grain size. Legend for B: 1, fi ne sand; 2, loess-like silty clay; 3, clay; 4, peat. From Yershov (1990).
Reproduced by permission of Cambridge University Press.
