An  in situ  X-ray topographic study was made of slip transmission through a grain boundary in hexagonal ice. It was found that, although the ice was deformed under creep conditions, the relative orientations of the grains and the orientation of the grain boundary with respect to the loading direction discouraged grain boundary sliding and therefore suppressed dislocation nucleation at the grain boundary. However, this geometrical arrangement was rarely encountered; thus suggesting that slip transmission through grain boundaries in ice was a rare event.

K.Jia, I.Baker, F.Liu, M.Dudley: Journal of Materials Science, 1996, 31[9], 2373-8