Permalink : http://hdl.handle.net/2115/45438

KEYWORDS : low angle grain boundary;creep test;dynamic recrystallization;recovery;sublimation grooves

Deformation microstructures in an Antarctic ice core (EDML) and in experimentally deformed artificial ice, which together comprise a great variety of conditions and parameters, are reconsidered and compared. Data presented here cover grain substructure and shape. Despite the different flow conditions surprising similarities in these observations indicate intracrystalline slip as the deformation carrier in natural as well as in experimentally deformed ice. Similar subgrain-boundary shapes and arrangements in both cases indicate characteristic types, which suggest that non-basal dislocations may play a significant role in the deformation of ice. Subgrain-boundary density and grain-boundary shapes show that a difference between processes in creep tests and in the Antarctic ice sheet is the efficiency of recovery and dynamic recrystallization.