Interference Phenomena in Deformed Single Crystals of Ice

• Published in: Journal of Glaciology
• Main Authors: Readings, G. J., Bartlett, J. T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1971
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s002214300001323x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300001323X

Abstract When rectangular single crystals of ice were subjected to uniaxial compression parallel to their Long axes and viewed between crossed polarizers, interference fringes were often observed. Some of these interference bands were associated with grain boundaries formed as a result of “kinking”. These can be explained in terms of the known anisotropic optical properties of ice and the change in the orientation of the optic axis across the boundary. This case has been analysed in detail with the aid of Jones’ calculus and good quantitative agreement exists between the theory and the experimental observations. Other interference bands were observed parallel to the trace of the basal plane on the surface of some deformed crystals. Alternative hypotheses for the explanation of this phenomenon have been considered and it seems probable that these bands are a result of slight random misorientations between adjacent slip lamellae. Applying Jones’ calculus to a simple model of such a deformed crystal indicates that the required misorientations are of the order of 1º If this explanation is correct, it implies that dislocations with non-basal Burgers vectors (probably c [0001]) make an active contribution to the deformation.