Geology Reference
In-Depth Information
(A)
Permafrost
extent
Continuous
Discontinuous
Widespread
Sporadic
Latitude
75°N
65°N
55°N
Mean annual
temperature
(°C)
-15°
-10°
-5°
0°
Active layer
~0.5 m
lake
lake
(i) thermokarst
depression
(ii) Active layer
~1.5 m
Surface terrain
conditions
50 m
tailk
taliks
Intrapermafrost
water
Permafrost
thickness
450 m
Groundwater
hydrology
Circulation
impeded or
absent
Circulation
impeded
Circulation
locally
impeded
No impediment
to groundwater
circulation
(B)
Figure
4.10.
Karst morphologies associated with permafrost terrain. (A) Karst-permafrost rela-
tions in the lowlands of northern Canada. (B) Nahanni karst, NWT. Both from Ford (1987), in
French and Slaymaker (1993). Reproduced by permission of McGill-Queens Press.
