firn line (limit) (English)

…A line that connects the lower limits of snow accumulation like this is sometimes called the snow line. In particular, when the lower limit of snow accumulation, i.e., the boundary between ice (glacier ice) and snow (firn) is at its highest at the end of summer, this is called the annual snow line or firn line (limit). The equilibrium line cannot be determined without calculating the glacier's mass balance (balance between recharge and depletion), but since the annual snow line can be seen with the naked eye, it is often used to determine the approximate position of the equilibrium line. …

*Some of the terminology that mentions "firn line (limit)" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…このように積雪の下限を連ねる線を雪線とよぶこともある。とくに，夏の終りに積雪の下限すなわち氷(氷河氷)と雪(フィルン)との境が最も高くなったとき，これを年的雪線annual snowlineまたはフィルン線firn line(limit)という。均衡線は氷河の質量収支(涵養と消耗のバランス)を計算しないと決定できないが，年的雪線は肉眼で識別できるので，均衡線の近似する位置を求めるために用いられることが多い。…

※「firn line（limit）」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報