Periglacial landforms
205
The disappearance of the vegetation cover with an insulating effect due to fires,
deforestation or construction may trigger the thawing of the permafrost. Other causes of
a geomorphological nature are thermal erosion due to stagnant water, or mass movement
processes such as slumps or mud flows that remove the active layer exposing the
permafrost (French, 1987).
Figure 8.37. Stages in the destruction of a pingo showing the development of a central depression with an
uplifted edge (Modified from De Gans, 1988).
205
The disappearance of the vegetation cover with an insulating effect due to fires,
deforestation or construction may trigger the thawing of the permafrost. Other causes of
a geomorphological nature are thermal erosion due to stagnant water, or mass movement
processes such as slumps or mud flows that remove the active layer exposing the
permafrost (French, 1987).
Figure 8.37. Stages in the destruction of a pingo showing the development of a central depression with an
uplifted edge (Modified from De Gans, 1988).