SNOW. 
85 
the wind and behaves like a sand-blast, cutting away both the soft and the 
hard layers. 
No transformation from snow to glacier-ice could be observed. Present climatic 
conditions are such that thawing, even partial thawing, only takes place very locally, 
and all the surfaces encountered were either granular white snow or compact ice. Even 
at the head of the Ferrar Glacier the change from snow to ice is absolutely sudden, 
and along the base of the great cascades the ice presents its characteristic rippled 
surface. Local accumulations of snow do occur in the larger depressions, but the line 
separating granular snow from glacier-ice is always sharp. A few snow-dunes were also 
seen, consisting of opaque white snow, too hard to be cut even with an iron spade. 
In 1902 Lieut. Arm it AGE travelled up Ferrar Glacier over soft snow, and at one 
of his camp-sites left pieces of spun 
yarn, a tin and a piece of wood ; 
they were found by our party 
a year later and lay loose upon 
hard transparent ice ; the tracks of 
his men and sledges could have 
been followed all the way up the 
glacier. The sledge-tracks appear 
as two parallel ridges, standing in 
relief nearly an inch above the 
general ice-level. The footprints 
of the men also stood in relief, 
but the dark objects left lying 
about were not so raised. From 
these facts it would seem that in 
this locality loss by ablation exceeds 
gain by precipitation. 
A surface of white snow absorbs 
little incident radiant heat. Owing; 
to the low temperature of the air, the growth of the grain can therefore only take 
place slowly. Iu sheltered spots or near bare rock, snow and ice melt rapidly during 
summer, and even in the open long furrows filled with water * appear. The best 
example of this was seen among the hummocks near Black Island, where long furrows 
filled with fresh water separate rows of hummocks ( Hug el f) from one another. 
Temperatures at fixed depths in the ice were determined during 1903, and the 
observations show that the variations from day to day are surprisingly small. It 
will suffice here to note that the highest temperature recorded at a depth of six feet 
was — 9 C. and the lowest —24 '4° C. The change was gradual throughout the year. 
* Drygalski, ‘ Gronland-Expedition,’ 1897, Bd. i, p. 78, plate. 
t Drygalski, 1 Gronland-Expedition,’ 1897, Bd. i, p. 86, plate. 
Fig. 49. — The two lower men are standing upon the 
UPPER SURFACE OF SEA-ICE DEPRESSED BY SNOW BELOW 
WATER-LEYEL. 
