Permafrost
Permafrost is ground that remains frozen throughout the year for at least two consecutive years. It ranges from a few metres to over 1000 m deep in some polar regions. The active layer above permafrost thaws seasonally.
Real World
In Yakutsk, Siberia, buildings are raised on stilts to prevent body heat melting the permafrost beneath, yet thawing ground has still caused over 300 residential buildings to deform since 2000.
Exam Focus
Define continuous, discontinuous, and sporadic permafrost using mean annual temperature thresholds to secure full definition marks.
How well did you know this?