Bandopadhyay et al. (1996 b) completed a finite element analysis of roof-to-floor convergence for entries in frozen material that accounted both material characteristics and heat transfer, It was shown that convergence was substantially dependent ambient air temperature. The first rapid deformation followed by a period of secondary creep in which closure rate was approximately constant. The relationship between convergence and span was found to be linear, even though the model accounted for nonlinear creep in the material. Figures 11.14 and 11.15 show results from the analysis. The simulations shown were made with an air temperature of-2.8°C and ground temperature of-4°C.