HR: 1330h
AN: C43A-01    [Abstracts]
TI: Effect of Dispersed Particles on Creep and Activation Energy of Granular Ice
AU: * Song, M
EM: Min.Song@Dartmouth.Edu
AF: Dartmouth College, Thayer School of Engineering, Hanover, NH 03755 United States
AU: Cole, D M
EM: David.M.Cole@erdc.usace.army.mil
AF: US Army, Cold Regions Research and Engineering Laboratory, Hanover, NH 03755 United States
AU: Baker, I
EM: Ian.Baker@Dartmouth.Edu
AF: Dartmouth College, Thayer School of Engineering, Hanover, NH 03755 United States
AB: The effects of silt-sized particles (1 wt. %) on the compressive creep of polycrystalline ice have been studied at temperatures from -20^oC to -2^oC. The particles were present both within the grains and along the grain boundaries. The results indicate that particles do not affect the power-law behavior. Both types of ice show power-law creep behavior with an exponent of 3 at temperatures from -20^oC to -2^oC, and the particles were found to increase the creep rates at temperatures lower than -5^oC. The effect of particles on creep rates decreases as temperature increases. At -2^oC, creep rates of both types of ice are compatible. Calculations indicate that activation energies of both types of ice are around 70 KJ mole^-1 when the temperature is between -20^oC to -10^oC. The activation energy shows a similar value for ice with particles but increases to around 120 KJ mole^-1 for particle-free ice when the temperature is above -10^oC. The increase in activation energy for particle-free ice can be explained by the increase in grain boundary sliding at high temperatures. Apparently, particles distributed along the grain boundaries inhibit the grain boundary sliding and thereby decrease the activation energy for ice with particles when the temperature is above -10^oC. This research was supported by NSF Office of Polar Programs, Arctic Natural Sciences Program (OPP 011737).
DE: 1863 Snow and ice (1827)
DE: 4540 Ice mechanics and air/sea/ice exchange processes
DE: 5462 Polar regions
DE: 6020 Ice
SC: Cryosphere [C]
MN: 2005 Joint Assembly