| Term: | Firn area |
| Definition: |
The zone of the glacier where the summer surface is underlain by firn instead of glacier ice. Changes in extent of the firn area, and thickness of the firn, complicate mass-balance calculations by the geodetic method since Sorge's law no longer applies. The firn area is not the same as the accumulation zone. IHPGlacierMassBalance
GCW |