Geology Reference
In-Depth Information
Table 6.1.
Temperature conditions for frost cracking.
Source
MAAT
Tair
ACR
Tsurf
GCRsurf
Ttop
GCRtop
Gradient
(°C)
(°C)
(°C/hr)
(°C)
(°C/day)
(°C)
(°C/day)
(°C/m)
Mackay, various papers,
−
7 to
−
9
−
29 to
−
34
−
0.1
<−
20
−
0.5 to
−
0.9
−
18 to
−
20
−
0.1 to 0.4
−
10 to
−
15
1973-2000
Allard and
−
8
−
25 to
−
43
−
0.2 to
−
0.6
−
21
−
0.9 to
−
1.7
−
15 to
−
20
−
0.6
≥−
10
Kasper (1998)
Fortier and
−
15
−
25 to
−
40
−
0.2 to
−
0.9
−
15 to
−
19
+
0.1 to
−
1.1
−
13 to
−
24
+
01. to
−
0.3
−
10.9
Allard (2005)
Christiansen (2005)
−
6
>−
25
n/a
−
15 to
−
20
n/a
−
15
−
0.3 to
−
0.4
n/a
MAAT - Mear Annual Air Temperature
Tair - Air temperature at time of frost cracking
ACR - Atmospheric cooling rate of cold spell
Tsurf - Temperature at or near the surface
GCRsurf - Ground cooling rate at surface prior to frost-cracking
Ttop - Ground surface temperature at time of frost cracking
GCRtop - Ground cooling rate at top of permafrost prior to frost cracking
Sources: Fortier and Allard (2005), Christiansen (2005). Reproduced by permission of John Wiley & Sons Ltd.
