| Term: | Freezing front |
| Definition: | The advancing boundary between frozen (or partially frozen) ground and Unfrozen Ground. In the usual case, where the Active Layer extends to the Permafrost Table, two Freezing Fronts will be present during annual freezing of the ground, one moving downward from the ground surface, the other moving upward from the Permafrost Table. The Freezing Front may not coincide with the 0C isotherm (Cryofront) due to freezing-point depressions. |