资源环境科技发展态势分析平台

Vast quantities of solid CO₂ reside in topographic basins of the south polar layered deposits (SPLD) on Mars and exhibit morphological features indicative of glacial flow. Previous experimental studies showed that CO₂ ice is 1–2 orders of magnitude weaker than water ice under Martian polar conditions. Here we present data from deformation experiments on pure, fine‐grained CO₂ ice, over a broader range of temperatures than previously explored (158–213 K). The experiments confirm previous observations of highly non‐linear power‐law creep at larger stresses, but also show a transition to a previously‐unseen linear‐viscous creep regime at lower stresses. We examine the viscosity of CO₂ within the SPLD and predict that (1) the CO₂‐rich deposits may be modestly stronger than previously thought, and (2) CO₂ ice flows much more readily than H₂O ice on the steep flanks of SPLD topographic basins, allowing the CO₂ to pond as is observed.