Geoscience Reference
In-Depth Information
Table 2.2
Typical values for thermal properties of various soil materials and soils
ρ
(kg m
-3
)
C
(J m
-3
K
-1
)
λ
(W m
-1
K
-1
)
κ
(m
2
s
-1
)
Material
c
(J kg
-1
K
-1
)
Soil components
a
Quartz
2.66·10
3
0.80·10
3
2.13·10
6
8.8
4.2·10
-6
Clay mineral
2.65·10
3
0.90·10
3
2.39·10
6
2.9
1.2·10
-6
Organic Matter
1.3·10
3
1.9·10
3
2.47·10
6
0.25
0.10·10
-6
Water
1.0·10
3
4.18·10
3
4.18·10
6
0.57
0.14·10
-6
Still air
1.2
1.004·10
3
1.2·10
3
0.025
21·10
-6
Sandy soil loosely packed (pore fraction 0.4)
a,b
Dry
1.60·10
3
0.80·10
3
1.28·10
6
0.24
0.19·10
-6
θ
= 0.2
1.80·10
3
1.18·10
3
2.12·10
6
2.1
0.99·10
-6
θ
= 0.4
2.00·10
3
1.48·10
3
2.96·10
6
2.5
0.85·10
-6
Sandy soil tightly packed (pore fraction 0.33)
a,b
Dry
1.78·10
3
0.80·10
3
1.42·10
6
0.29
0.20·10
-6
θ
= 0.15
1.93·10
3
1.06·10
3
2.05·10
6
2.5
1.2·10
-6
θ
= 0.33
2.11·10
3
1.33·10
3
2.81·10
6
2.9
1.0·10
-6
Clay soil (pore fraction 0.4)
a
Dry
1.59·10
3
0.90·10
3
1.43·10
6
0.15
0.10·10
-6
θ
= 0.2
1.79·10
3
1.27·10
3
2.27·10
6
0.9
0.4·10
-6
θ
= 0.4
1.99·10
3
1.56·10
3
3.10·10
6
1.4
0.45·10
-6
Peat soil (pore fraction 0.9)
a,c
Dry
0.13·10
3
1.90·10
3
0.25·10
6
0.04
0.16·10
-6
θ
= 0.45
0.58·10
3
3.67·103
2.13·10
6
0.27
0.13·10
-6
θ
= 0.90
1.03·10
3
3.89·10
3
4.01·10
6
0.50
0.12·10
-6
Other materials
d
Rock
2.7·10
3
0.75·10
3
2.03·10
6
2.9
1.4·10
-6
Ice
0.9·10
3
2.09·10
3
1.88·10
6
2.5
1.3·10
-6
Fresh snow
0.2·10
3
2.09·10
3
0.42·10
6
0.1
0.3·10
-6
Old snow
0.8·10
3
2.09·10
3
1.67·10
6
1.7
1.0·10
-6
Note that these properties are temperature dependent. Values given here are representative for
temperatures in the range 10-20 °C (different sources use different reference temperatures).
Data from:
a
De Vries (
1963
) (see Clauser and Huenges, 1995, for a more extensive review of
conductivities of soil minerals and rocks);
b
Smits et al. (
2010
);
c
O'Donnell et al. (
2009
);
d
Lee
(
1978
).
makes a large difference. The water will be concentrated in the narrowest parts of the
pores (see
Chapter 4
), that is, close to the contact points between the soil particles.
The addition of only a little water will increase the area of contact greatly. Although
the conductivity of water is smaller than that of the material of the particles, it is
much higher than that of air. As a result the total pathway for heat transport increases.
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