| Term: | Permafrost boundary |
| Definition: | 1. The geographical boundary between the continuous and discontinuous permafrost zones; 2. The margin of a discrete body of permafrost. |
| Term: | Permafrost boundary |
| Definition: | 1. The geographical boundary between the Continuous and Discontinuous Permafrost zones in Arctic and Antarctic environments; 2. the boundary between the existence of mountain permafrost and no permafost in mountainous environments; or 3. the margin of a discrete body of Permafrost. |
| Term: | Permafrost boundary |
| Definition: | (1) the geographical boundary between the continuous anddiscontinuous permafrost zones(2) the margin of a discrete body of permafrost. |