Geology Reference
In-Depth Information
11.4.2. Relict Permafrost
Ice sheets may destroy, inhibit, preserve, or stimulate the growth of permafrost beneath
the ice. This depends upon the thickness of the ice body, its cold- or warm-based nature,
and its duration. Likewise, the cold-climate conditions that induced the ice sheets would
cause the formation of permafrost in adjacent ice-free terrain. In general, one can envisage
thick and cold permafrost in never-glaciated terrain and thinner or non-existent perma-
frost beneath ice sheets. If permafrost that formed during one cold period is preserved
into the following cold period and then overridden by ice, complex permafrost bodies
may result. For example, Figure 11.7 provides schematic illustrations of the sorts of
relationships that might exist between permafrost thickness and the nature and extent
Figure 11.7. Diagram showing simplifi ed relationship between the growth and decay of perma-
frost. (A) Cold-/warm-based ice sheets; (B) climatic fl uctuations. From Romanovskii (1993).
Search WWH ::




Custom Search