A Deformation Mechanism Map of Ice

• Published in: Journal of Glaciology
• Main Authors: Shōji, H., Higashi, A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1978
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s002214300003358x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300003358X

Abstract A deformation mechanism map for pure polycrystalline ice of 2 mm grain diameter is constructed, New sub-regions in the dislocation glide region are proposed: dislocation glide with crack formation, dislocation creep, and fracture at high stresses above about 1 MPa. The boundary between the dislocation creep and DGC regions is determined by the onset of cleavage cracks due to piled-up dislocations near grain boundaries. The fracture region is that area of the map where fracture occurs readily when the ice is subjected to a rapid deformation rate exceeding 10 -3 s -1 . Experimental results of the stress dependence of the compressive deformation rate of polycrystalline ice are compared with the map. The effect of changes in the creep activation energy near the melting point is discussed together with those of other factors.