祁连山老虎沟12号冰川冰下形态特征分析

利用探地雷达对老虎沟12号冰川进行了多个剖面观测,分析了雷达图像反映的冰川内部特征.结果表明通过分析雷达图像中的纹理和位置,雷达波形的振幅和极性变化等信息能够有效的辅助识别冰川内部介质的变化界面位置和估算其规模.在老虎沟12号冰川的部分剖面内部存在冰内空洞、冰内融水空洞、冰下裂隙、冰下河等地貌形态,在冰岩界面和冰川边缘存在规模不等的碎屑层.这说明即使在典型的大陆型冰川,冰川内部结构也可能较为复杂,在冰岩界面处可能存在较强的冰川作用.

Structural Characteristics of the No. 12 Glacier in Laohugou Valley, Qilian Mountain Based on the Ground Penetrating Radar Sounding

The inner-structure of glacier was analyzed from the profile images of ground-penetrating radar at No.12 Glacier in Laohugou Qilian Mountain western China. By calculating the difference of dielectric constants among water, air, bedrock, debris and ice, integrated with changes in radar wave polarity and velocity, the geomorphic character within the glacier was described and caves, caves with water, channels beneath the ice, the interface between glacier and bedrock were identified and positioned, with the comparison of wave patterns introduced in some literatures. The results suggest that there exist debris layers between ice-bedrock interfaces indicating that strong basal erosional processes may even prevail in certain part of a glacier of the continental characteristic, contrary to the early knowledge about this kind of glaciers.