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Ice fabric evolution process understood from anisotropic distribution of a-axis orientation on the GRIP (Greenland) ice core
Title: | Ice fabric evolution process understood from anisotropic distribution of a-axis orientation on the GRIP (Greenland) ice core |
Authors: | Miyamoto, Atsushi Browse this author | Shoji, Hitoshi Browse this author | Hori, Akira Browse this author | Hondoh, Takeo Browse this author →KAKEN DB | Clausen, Henrik B. Browse this author | Watanabe, Okitsugu Browse this author |
Keywords: | ice core | fabric | a-axis orientation | mechanical property |
Issue Date: | Aug-2005 |
Publisher: | International Glaciological Society |
Journal Title: | Annals of Glaciology |
Volume: | 42 |
Start Page: | 47 |
End Page: | 52 |
Publisher DOI: | 10.3189/172756405781812501 |
Abstract: | To better understand how ice fabric evolves in polar ice sheets, we use X-ray diffraction to measure ice crystal orientations. X-ray measurement equipment which can measure the orientation of the c axis and a axis of each crystal in a thin section with high measurement accuracy was developed. In this study, we present a-axes orientation distribution of the deep part of the GRIP (Greenland summit) ice core. At some depths, we find an anisotropic distribution of a-axes orientation. Long-term uniaxial compression tests are also carried out on the GRIP ice core to investigate the ice fabric evolution process. The c-axis orientation distribution develops into a stronger single maximum as the strain increases up to about 20% strain. We find that the a axes of each grain also tend to cluster close to nearly a mutual direction. We discuss the development process of ice fabrics, taking into consideration the distribution of the a-axis orientations. It is suggested that these fabrics may be attributed to a local simple shear deformation in the deep part of an ice sheet. |
Rights: | © 2005 International Glaciological Society |
Relation: | http://www.igsoc.org/ |
Type: | article |
URI: | http://hdl.handle.net/2115/34754 |
Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 宮本 淳
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