Investigations of internal structure and transformational processes from firn to ice in a perennial snow patch
Investigations of internal structure and transformational processes from firn to ice in a perennial snow patch
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常年雪地内部结构和从雪到冰的转变过程的研究
DOI：
10.3189/s0260305500011368
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发表时间：
1993
影响因子：
2.9
通讯作者：
G. Wakahama
中科院分区：
文献类型：
--
作者：
K. Kawashima;Tomomi Yamada;G. Wakahama
为了研究日本北海道大泽山Hisago雪斑的内部结构和从雪到冰的转化过程，在1986和1987年的消融期间进行了多次钻探。对冰芯进行了地层、密度和自由水含量分析。雪片的内部结构特征是湿润的积雪层，上面覆盖着4.3米厚的冰体，上面覆盖着丰富的冰层和冰腺。降雪层厚度由6月的12.7米至10月的1.3米不等。一层厚度约为1米的饱和积雪层正好位于冰火过渡的上方。年度冰层由污泥层识别，这表明当质量收支为正数时，每年形成1-2米的冰。尽管饱和积雪层的致密化进行得很快，但在消融过程中，从积雪到冰的转变并不明显。结果表明，冰体的形成机制包括三个过程：叠加冰的形成、饱和积雪层的致密化和寒潮穿透冻结湿积雪和/或饱和积雪。
To investigate the internal structure and transformational processes from firn to ice of the Hisago snow patch on Daisetsu Mountain, Hokkaido, Japan, many drillings were made during the ablation period in 1986 and 1987. The ice cores were analyzed for stratigraphy, density and free water content. The internal structure of the snow patch was characterized by a wet firn layer with abundant ice layers and ice glands overlying a 4.3 m-thick ice body. The thickness of the firn layer varied from 12.7 m in June to 1.3 m in October. A water-saturated firn layer about 1 m thick existed just above the firn-ice transition. The annual layers were identified by dirt layers which showed that 1–2 m of ice was formed each year when the mass budget was positive. Although the densification of the water-saturated firn layer proceeded rapidly, the transformation from firn to ice could not be recognized during the ablation period. It was concluded that the formation mechanism of the ice body comprised three processes: the formation of superimposed ice, the densification of a water-saturated firn layer and the freezing of wet and/or water-saturated firn by cold wave penetration.