Also: Firn Line
Firn is snow that has survived a complete season of ablation, typically on a glacier.
Climbers often use the term a bit more loosely to indicate snow which is similar to that which has survived a year, whether or not it has. Such snow has a firm styrofoam consistency which is very good for using an ice axe and crampons and is often found by mid to late summer even from the previous winters snowfall.
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