Flow-Law Parameters of the Dye 3, Greenland, Deep Ice Core
Flow-Law Parameters of the Dye 3, Greenland, Deep Ice Core
复制标题
染料 3 的流动定律参数，格陵兰岛，深冰芯
作者：
H. Shoji;C. C. Langway
对格陵兰岛Dye 3冰芯268、1890、1944和2006 m深度的22个新试件进行了十字头恒速单轴压缩试验。在实验室冷室中使用Instron 1131型装置进行测量。测试温度保持在−17° C和−13° C之间，这是近似的样品原位温度。制备了相对于长垂直芯轴具有各种测试方向的试样。对样本进行了灰尘含量、Cl−、NO3 −和SO4 2−浓度以及各种其他物理参数（如超声波速度、c轴取向模式和粒度）的分析。以往的单轴压缩试验结果表明，大部分的流动发生在威斯康星时代的冰之间的1786米和冰盖底部。这整个深度区间是强烈的各向异性，垂直的c轴织物图案。从这些测试计算的增强因子E的范围为0.03至17。威斯康星时代的冰大约比人工制造的实验室冰（E = 1）软10倍（Es = 10）。多参数相关性分析的综合结果表明，E主要由c轴的取向强度控制，杂质浓度水平的变化贡献较小。
Uniaxial compression tests under constant crosshead speed were carried out on 22 new specimens from the 268, 1890, 1944 and 2006 m depths of the Dye 3, Greenland, ice core. The measurements were made in a laboratory cold-room, using an Instron model 1131 apparatus. Test temperatures were held constant between −17° and −13° C, the approximate sample in-situ temperature. Specimens were prepared with various test orientations in relation to the long vertical core axis. The specimens were analyzed in terms of the content of dust, Cl−, NO3 − and SO4 2− concentrations and various other physical parameters, such as ultrasonic wave velocities, c-axis orientation patterns and grain-size. The results of the previous uniaxial compression tests show that most of the flow occurs in the Wisconsin-age ice between 1786 m and the bottom of the ice sheet. This entire depth interval is strongly anisotropic, with a vertical c-axis fabric pattern. The enhancement factor, E, which was calculated from these tests ranges from 0.03 to 17. The Wisconsin-age ice is about ten times softer (Es = 10) than artificially made laboratory ice (E = 1). The combined results of the multi-parameter correlation analyses show that E is controlled primarily by the orientation strength of c-axes and that the impurity concentration-level variations contribute to a lesser degree.