A rapidly moving small rock glacier at the lower limit of the mountain permafrost belt in the Swiss Alps
A rapidly moving small rock glacier at the lower limit of the mountain permafrost belt in the Swiss Alps
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瑞士阿尔卑斯山永久冻土带下限的快速移动的小岩石冰川
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Atsushi Ikeda
中科院分区：
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作者：
Atsushi Ikeda
对上恩嘎丁的一个小型距骨岩石冰川的表面和内部运动、结构和热条件进行了研究。在岩石冰川上部钻出的 5.4 m 深的钻孔显示了冰饱和沉积物，由卵石、鹅卵石和细碎屑组成。地面最上面 5 m 范围内年平均气温接近 0°C。虽然下部仅轻微向下倾斜，但上部却显示出快速移动（50-150 cm a 1），并在三年内加速移动。测斜仪还显示出永久冻土在深处的巨大变形。直流电阻率断层图显示永久冻土厚度小于 20 m。接近熔点的永久冻土变形迅速，对地温的年际变化敏感。这种快速移动被认为是暂时的，最终由于永久冻土融化和碎片输入的缺乏而导致岩石冰川失活。 Permafrost、Phillips、Springman 和 Arenson（编辑）© 2003 Swets & Zeitlinger, Lisse，ISBN 90 5809 582 7
Surface and internal movements, structure and thermal conditions were investigated on a small talus-derived rock glacier in the Upper Engadin. A borehole 5.4 m deep drilled on the upper part of the rock glacier displayed ice-saturated sediments, consisting of pebbles, cobbles and fine debris. The mean annual temperatures were close to 0°C within the uppermost 5 m of ground. Whereas the lower part moved downslope only slightly, the upper part showed rapid movement (50–150 cm a 1), accelerating over a 3-year period. Inclinometers also showed large deformation of permafrost at depth. A DC resistivity tomogram indicates that permafrost is thinner than 20 m. Permafrost close to the melting point is deformed rapidly and is sensitive to inter-annual variation in ground temperature. Such rapid movement is considered to be temporary and eventually followed by inactivation of the rock glacier because of permafrost melting and a lack of debris input. Permafrost, Phillips, Springman & Arenson (eds) © 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 582 7