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Show spiraled on, globoid and sometimes cylindrical or discoid, seldom over 50 cm in diameter, characteristic of wet snow, fragments of which have rolled coatings of sub- slide snow over themselves; 3) slabs - fragments of extremely hard snow layers, preserving a layered structure and angularity, up to 2- 3 m3 in volume; 4) rolled balls - fragments of not too hard snow that have lost their angularity and acquired an ovoid form in their motion, sometimes showing a laminated structure and having the appearance of the masses under 1), but much harder; 5) compressed masses - extremely dense, solid, rounded chunks, formed of snow milled and then compressed by avalanche movement, measuring 30- 50 cm, sometimes up to 2 m, found with avalanches of dense, ground snow and wet granular snow, non- homogeneous in structure, often containing stones, tree branches and other inclusions, density not less than 0.40. For a given avalanche the snow balls and chunks in the terminal deposit are more or less uniform in size, and only in large- scale slides do they differ greatly in dimensions and structure; in this case they are sorted and clumped in certain areas of the deposit, the larger masses to the fore. Sometimes, expe-cially large snow plates at the top of the avalanche coast ahead of the terminal deposit when the slide dies, planing out smooth tracks several meters long. The snow density in the fore part of an avalanche deposit, and around obstacles, is always greater than at the tail. Density increases with depth, though some horizons ( levels) may have a greater density than those above. As examples, we cite snow densities in an avalanche of December 22, 1936, on Mount Aykuayventchorr. Snow specimens were taken at 50 cm intervals of depth; total thickness of the deposit was 8 m. Table 7 Snow Density in Terminal Deposit of Avalanche of Dec. 22, 1936 ( from top down) Specimen N o . 1 2 3 4 5 6 7 8 Density 0.37 0.37 0.45 0.47 0.48 0.51 0.46 0.52 Specimen No. 9 10 11 12 13 14 15 16 Density 0.49 0.50 0.49 0.50 0.52 0.53 0.51 0.50 The looser the primary snow, the more pronounced is the increase in density with depth. For example, in the deposit of an avalanche of February 3, 1936, on the southwest slope of Mount Ukspor, the densities of specimens tested at 50 cm intervals of depth were 0.12, 0.21, 0.27 and 0.35, and average of 0.24. In slides of dense snow, density does not vary greatly. In an avalanche of January 8, 1935, on the southwest slope of Mount Ukspor, the average density of the break- away step was 0.42; of the dump, 0.44; of the compressed blocks in the dump, 0.46. Where a dump is formed by the deposits of more than one avalanche, - 37- |