| Term: | Permafrost region |
| Definition: | A region in which the temperature of some or all of the ground below the seasonally freezing and thawing layer remains continuously at or below 0 degrees Celsius for at least two consecutive years. |
| Term: | Permafrost region |
| Definition: | A region in which the temperature of some or all of the ground below the seasonally freezing and thawing layer remains continuously at or below 0˚C for at least two consecutive years |