Slab calving from an ice wall on Deception Island (63.0°S, 60.6°W) has been related to a bending moment at the top of the ice wall that produced nearly vertical shear bands across which shear offset decreases to zero at the bed and in which strain-rates up to 600/a were measured. These shear bands and strain-rates were duplicated in laboratory creep experiments at shear stresses of 100 kPa or more, after a shear strain of about 0.4 at the end of recrystallization. Recrystallization began at a shear strain of about 0.1 when the strain-rate was about 1.9/a, which increases to 24.0/a after recrystallization. Halving the shear stress suppressed recrystallization. Prior to recrystallization, n = 2.17 in the flow law,