Figure 17.3

Periglacial features. (A) Continuous permafrost occurs where the permafrost is 100 m (330 ft) thick or more. Permafrost that is thinner and interrupted by unfrozen ground, called talik, is discontinuous permafrost. (B) Permafrost is widely distributed throughout the Northern Hemisphere. This map shows discontinuous and continuous permafrost areas as well as areas with sporadic and isolated permafrost.