844 DR J. H. HARVEY PJRIE ON 



by a vertical ice-cliff washed by the sea at high-water. The rocks are very low, and 

 were the glacier advancing it would easily override them, and end in one continuous 

 cliff of ice, where the sea either broke it off by floating up or by undermining. That 

 the glaciers here are now either stationary or retreating is further borne out by the 

 moraines and by some exposed rock surfaces. 



Terminal Ice-Cliffs. 



As the terminal cliff- faces give the best available sections of a glacier, it is 

 unfortunate that the conditions for studying them were not more favourable. When 

 we entered Scotia Bay on 25th March the lower parts of the ice-cliffs bordering it 

 were entirely hidden to a height of some 30 or 40 feet by an accumulation, composed 

 partly of blocks fallen from the cliffs, but mainly of drift snow. The presence of this 

 showed that during the summer 1902-03 the ice in the bay had been very late in 

 breaking up (probably only a few days before our entry), and also that there had always 

 been enough pack-ice around the islands to prevent any swell getting into the bay to 

 break up the land-floe and wash away this talus. This, in fact, we experienced when 

 trying to approach the islands in the beginning of February 1903 ; and, when looking 

 for a harbour on 24th March, heavy pack-ice extended from south and west right up to 

 the islands. In the spring of 1903 the land-floe broke up on 23rd November, but it was 

 not until the end of January 1904 that any part of the sole of these glaciers was 

 exposed, and even on the 22nd February, when we quitted the South Orkneys, there was 

 still a considerable amount of the talus left in places. This accumulation must therefore 

 have been in position at least from early in 1902 till the time we left, i.e. two years — a 

 good indirect proof of the slow rate of motion of these glaciers. 



The trifling amount of ice-falls from the cliffs witnessed during the winter season 

 of 1903 and the summer 1903-04 is another indication of their slow movement 

 (see p. 854). 



As the ice-cliffs around Scotia Bay were naturally those best examined, and were 

 in point of fact the only faces in which the whole depth of the cliff was seen, a more 

 detailed description of them may be given, but with local modifications it would apply 

 to the ice-cliffs in general around the island (see Plate VI.). 



The terminal cliff of any particular ice-sheet is usually remarkably regular in height, 

 varying in different cases from about 60 to 160 feet, but running, as a rule, and as in the 

 case of the Scotia Bay ice-sheet, about 120 or 130 feet. Although in plan appearing 

 usually as slightly concave or as a series of curves, concave towards the sea, the face at 

 any particular point is usually fairly flat, with few crevasses, and the irregularities of 

 its surface are small. The clifl" is either vertical or slightly overhanging, especially in 

 the case of the top portion. The whole face shows a very even horizontal stratification. 

 The upper layers are composed of granular neve, with thin bands of ice \ inch to 

 2 inches in thickness ; on a broken-off" piece the line of demarcation between the n6v6 

 and the hard glacier ice is not absolutely sharp, though there is a place where the change 



