| Term: | Relict active layer |
| Definition: | A layer of ground, now perennially frozen, lying immediately below the modern active layer; its thickness indicates the greater annual depth of thaw that occurred during a previous period. |
| Term: | Relict active layer |
| Definition: | A layer of ground, now perennially frozen, lying immediately below the modern active layer. Its thickness indicates the greater annual depth of thaw that occurred during a previous period |
| Term: | Relict active layer |
| Definition: | A layer of ground, now perennially frozen lying immediately below the modern Active Layer. Its thickness indicates the greater annual Depth of Thaw that occurred during a previous period. |