Complete determination of ice crystal orientation using Laue X-ray diffraction method
Ice crystal orientation fabric data from ice cores contain important information concerning the internal structure and the flow behaviour of ice sheets. When ice cores are recovered from the Antarctic and Greenland ice sheets, crystal orientation measurements are performed immediately to obtain fund...
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fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/47908 2023-05-15T13:42:36+02:00 Complete determination of ice crystal orientation using Laue X-ray diffraction method Miyamoto, Atsushi Weikusat, Ilka Hondoh, Takeo http://hdl.handle.net/2115/47908 eng eng International Glaciological Society http://www.igsoc.org/ http://hdl.handle.net/2115/47908 Journal of Glaciology, 57(201): 103-110 © 2011 International Glaciological Society 450 article fthokunivhus 2022-11-18T01:02:07Z Ice crystal orientation fabric data from ice cores contain important information concerning the internal structure and the flow behaviour of ice sheets. When ice cores are recovered from the Antarctic and Greenland ice sheets, crystal orientation measurements are performed immediately to obtain fundamental physical property information. In the past, we have measured the c-axis orientation of ice crystals by a manual optical method using a universal stage. This method is very time-consuming, involving tedious work in a cold laboratory. Recently, automated systems have been developed that enable measurement of c-axis orientation, grain size and other microstructures. However, in order to detect the full crystal orientation of an ice crystal, we also need information on its a-axis orientation. A variety of other crystal orientation measurement methods have previously been discussed, but some shortcomings for ice-core studies cannot be neglected. We have developed a crystal-orientation analysing device using the Laue X-ray diffraction method. As this device can measure the orientations of all crystal axes with high accuracy, it is possible to obtain new microstructure information on natural ice crystals. For the first time, we are able to quantify very low subgrain misorientation angles in polar icecore samples, allowing us to investigate micro-deformation features of individual crystals. Here we discuss the analysis process, which is customized to measure standard ice thin sections, and show preliminary results. Article in Journal/Newspaper Antarc* Antarctic Greenland ice core Journal of Glaciology Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Antarctic Greenland The Antarctic |
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Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
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English |
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450 Miyamoto, Atsushi Weikusat, Ilka Hondoh, Takeo Complete determination of ice crystal orientation using Laue X-ray diffraction method |
topic_facet |
450 |
description |
Ice crystal orientation fabric data from ice cores contain important information concerning the internal structure and the flow behaviour of ice sheets. When ice cores are recovered from the Antarctic and Greenland ice sheets, crystal orientation measurements are performed immediately to obtain fundamental physical property information. In the past, we have measured the c-axis orientation of ice crystals by a manual optical method using a universal stage. This method is very time-consuming, involving tedious work in a cold laboratory. Recently, automated systems have been developed that enable measurement of c-axis orientation, grain size and other microstructures. However, in order to detect the full crystal orientation of an ice crystal, we also need information on its a-axis orientation. A variety of other crystal orientation measurement methods have previously been discussed, but some shortcomings for ice-core studies cannot be neglected. We have developed a crystal-orientation analysing device using the Laue X-ray diffraction method. As this device can measure the orientations of all crystal axes with high accuracy, it is possible to obtain new microstructure information on natural ice crystals. For the first time, we are able to quantify very low subgrain misorientation angles in polar icecore samples, allowing us to investigate micro-deformation features of individual crystals. Here we discuss the analysis process, which is customized to measure standard ice thin sections, and show preliminary results. |
format |
Article in Journal/Newspaper |
author |
Miyamoto, Atsushi Weikusat, Ilka Hondoh, Takeo |
author_facet |
Miyamoto, Atsushi Weikusat, Ilka Hondoh, Takeo |
author_sort |
Miyamoto, Atsushi |
title |
Complete determination of ice crystal orientation using Laue X-ray diffraction method |
title_short |
Complete determination of ice crystal orientation using Laue X-ray diffraction method |
title_full |
Complete determination of ice crystal orientation using Laue X-ray diffraction method |
title_fullStr |
Complete determination of ice crystal orientation using Laue X-ray diffraction method |
title_full_unstemmed |
Complete determination of ice crystal orientation using Laue X-ray diffraction method |
title_sort |
complete determination of ice crystal orientation using laue x-ray diffraction method |
publisher |
International Glaciological Society |
url |
http://hdl.handle.net/2115/47908 |
geographic |
Antarctic Greenland The Antarctic |
geographic_facet |
Antarctic Greenland The Antarctic |
genre |
Antarc* Antarctic Greenland ice core Journal of Glaciology |
genre_facet |
Antarc* Antarctic Greenland ice core Journal of Glaciology |
op_relation |
http://www.igsoc.org/ http://hdl.handle.net/2115/47908 Journal of Glaciology, 57(201): 103-110 |
op_rights |
© 2011 International Glaciological Society |
_version_ |
1766170106502578176 |