EBSD analysis of subgrain boundaries and dislocation slip systems in Antarctic and Greenland ice
Ice has a very high plastic anisotropy with easy dislocation glide on basal planes while glide on non-basal planes is much harder. Basal glide involves dislocations with Burgers vector b= , while glide on non-basal planes can involve dislocations with b= , b=[c] and b=<c+a>. During natural duc...
Main Authors: | , , , , |
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Format: | Dataset |
Language: | English |
Published: |
PANGAEA
2017
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Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.879614 https://doi.org/10.1594/PANGAEA.879614 |
Summary: | Ice has a very high plastic anisotropy with easy dislocation glide on basal planes while glide on non-basal planes is much harder. Basal glide involves dislocations with Burgers vector b= , while glide on non-basal planes can involve dislocations with b= , b=[c] and b=<c+a>. During natural ductile flow of polar ice sheets most of the deformation is expected to occur by basal slip accommodated by other processes including non-basal slip and grain boundary processes, however the importance of different accommodating processes is controversial. The recent application of micro-diffraction analysis methods to ice such as X-ray Laue diffraction and electron backscattered diffraction (EBSD) has demonstrated that subgrain boundaries indicative of non-basal slip are present in naturally deformed ice, although, so far the available data sets are limited. In this study we present an analysis of a large number of subgrain boundaries in ice core samples from one depth level from two deep ice cores, from Antarctica (EPICA-DML deep ice core at 656 m depth) and from the Greenland (NEEM deep ice core at 719 m depth). |
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