The effect of temperature on the ductile-to-brittle transition in columnar ice

Experiments on S2 ice (fresh-water ice and salt-water ice) under uniaxial compression were performed at strain rates between 10(6) s(-1) to 10(-1) s(-1) at temperatures from -3 degrees C to -40 degrees C. The results showed that over this range the ductile-to-brittle transition strain rate for both fresh-water ice and salt-water ice decreases by almost an order of magnitude with decreasing temperature. The transition strain rate in salt-water ice is one order of magnitude higher than that in fresh-water ice. The apparent activation energy increases with increasing temperature, from 73.5 kJ/mole at -40 degrees C to 78.5 kJ/mole at -3 degrees C in the fresh-water ice, and from 60.9 kJ/mole at -40 degrees C to 63.4 kJ/mole at -3 degrees C in the salt-water ice.