Ice-fabrics study in the upper 1500 m of the Dome C (East Antarctica) deep ice core
Ice-fabrics study in the upper 1500 m of the Dome C (East Antarctica) deep ice core
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Dome C（南极洲东部）深冰芯上部 1500 米的冰结构研究
DOI：
10.3189/172756403781816031
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发表时间：
2003
影响因子：
2.9
通讯作者：
H. Miller
中科院分区：
文献类型：
--
作者：
Yun Wang;S. Kipfstuhl;N. Azuma;T. Thorsteinsson;H. Miller
摘要利用冰组构自动分析仪（AIFA）对东南极冰穹C冰芯上部1500米深冰芯的c轴方向进行了研究。分析了来自岩心不同深度的29个垂直薄片和一些水平薄片。几个统计参数描述织物的强度和织物的形状已经计算出的c轴取向数据。结构图显示了一个近乎随机的c轴方向分布在冰盖的最上部。在所研究的区间的最低部分观察到一个广泛的单一最大织物的c轴旋转的趋势。因此，冰穹C处的组构发展对于冰盖峰顶和冰穹场地来说是典型的。冰穹C的结构发展与冰穹F和GRIP冰芯的结构演变进行了比较，并给出了用图像分析技术获得的晶体尺寸数据。相邻晶体的c轴之间的取向差角的研究显示，几乎没有证据的结晶，但显微镜观察表明，亚晶界存在于任何深度的晶粒的一半。
Abstract A study of c-axis orientations in the upper 1500m of the Dome C (East Antarctica) deep ice core has been carried out using an automatic ice-fabric analyzer (AIFA). Twenty-nine vertical and a few horizontal thin sections from different depths in the core have been analyzed. Several statistical parameters describing fabric strength and fabric shapes have been calculated from the c-axis orientation data. The fabric diagrams display a near-random c-axis orientation distribution in the uppermost parts of the ice sheet. A tendency of c-axis rotation towards a broad single-maximum fabric is observed in the lowest part of the studied interval. The fabric development at Dome C thus appears typical for ice-sheet summit and dome sites. The fabric development at Dome C is compared with the fabric evolution in the Dome F and GRIP ice cores, and data on crystal size obtained with image-analysis techniques are presented. Studies of misorientation angles between the c axes of neighbouring crystals reveal little evidence for polygonization, but microscopic observations show that sub-grain boundaries are present in half of the grains at any depth.