Synthesis and rheology of fine-grained ice II at high pressures and low temperatures

Abstract

Creep experiments on polycrystalline water ice II with a variety of grain sizes (6-38 micron) have been performed at conditions relevant to planetary interiors (confining pressures of 200-250 MPa and temperatures of 200-220 K). Clear differences in creep behavior have been observed with different grain sizes at constant strain rates of 1.4e-8-4.3e-6 (s-1). The grain-size sensitive creep of ice II demonstrated here plausibly dominates plastic strain at the low stress conditions in the interior of medium- and large-size icy moons of the outer solar system