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标题：X-ray microtomography analysis of isothermal densification of new snow under external mechanical stress
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作者：Stefan Schleef ; Henning Löwe
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2013
卷号：59
期号：214
页码：233-243
DOI：10.3189/2013JoG12J076
出版社：Cambridge University Press
摘要：We have investigated the isothermal densification of new snow under an external mechanical stress. New snow samples that mimic natural snow were made in the laboratory by sieving ice crystals grown in a snowmaker. This allowed us to assemble homogeneous initial samples with reproducible values of low density and high specific surface area (SSA). Laboratory creep experiments were conducted in an X-ray microtomograph at −20°C for 2 days. We focused on the evolution of density and SSA as a function of constant stress at a single temperature. External mechanical stresses resembled natural overburden stresses of a snow sample at depths of ∼0–30 cm of new snow. We demonstrate that densification increases with higher external stress and lower initial densities. We find that the evolution of the SSA is independent of the density and follows a unique decay for all measurements of the present type of new snow. The results suggest that details of the SSA decrease can be investigated using carefully designed experiments of short duration which are convenient to conduct. Additionally, we calculated the strain evolution and identify transient creep behavior that does not follow the Andrade creep law of denser snow or polycrystalline ice.