Laboratory studies on relationships between ice crystal size and flow rate

Three sets of uniaxial compression experiments on polycrystalline ice are described. Five separate ice samples, each with a different crystal size, were represented, and minimum strain rate was attained for all tests. A tertiary creep stage was reached for each set of tests, and for one set this is examined in detail. All sets of tests demonstrated little or no dependence of the minimum ice strain rate on crystal size. In tertiary creep the strain rates were in closer agreement than at minimum. Beyond the minimum strain rate, crystal size was found to change during the development of the tertiary creep stage, such that on termination of the experiment, all crystal sizes were approximately the same. It is concluded, for the range of strain rates covered, that tertiary ice flow may limit crystal growth to an equilibrium size.