GLACIOLOGY OF THE SOUTH ORKNEYS. 833 



(iii.) Piedmont glaciers. Under this heading he includes such apparently divergent 

 forms as (a) shelf-ice like the Ross Barrier, and (b) the type called by ARgxowsKi " slope 

 glaciers" or "suspended coastal glaciers" ("glaciers adosses ou cotiers," " gehiinge- 

 gletscher"), and by Nordenskjold, " ice -foot glaciers." These all form a high terrace 

 along the sea border, and have no separate zone of accumulation. With regard to group 

 (b), he states that they are the most characteristic Antarctic form — in the west of 

 Graham Land they form a continuous terrace all along the coast, save where the moun- 

 tains plunge directly into the sea. They terminate in a cliff from 15 to 20 m. high, 

 have a uniform surface covered with snow, a gentle slope to the shore, and a surface 

 showing a concave curve up to the hills behind. The terminal ice-face, as with other 

 Antarctic glaciers, shows well-marked horizontal stratification ; crevasses are rare, but 

 vertical or zig-zag fissures are common. These glaciers are all breadth, their length in 

 the direction of flow being always short, simply the distance between the sea and the 

 mountains behind. They are nourished by local precipitation, occasionally also by ava- 

 lanches from the hills above. Their potentiality is a simple function of the plasticity of 

 ice — when that tends to be passed blocks fall otf and equilibrium is re-established. 



(iv.) Ice-foot. A transition form between terrestrial and marine ice formations. 



(d) Hohhs. — HoBBS (5) sums up briefly the characters and classification of the types 

 of ice formation with which we have to deal in the South Orkneys. " Where the islands 

 are higher, the snow either wholly or in part is blown by the wind from the higher 

 surfaces into the lee of the hills and thus forms a fringing zone of the ice-foot. Such 

 a fringing ice-foot is illustrated by Sturge Island of the Balleny Group to the north 

 of Victoria Land (6). The ice-foot surrounding a land mass represents a type of 

 fringing glacier not unlike those described by Chamberlin and Peary from Northern 

 Greenland (7). For long distances these marginal bands of rather steeply sloping 

 snow and ice bound the elevated land, and have in consequence been called by Otto 

 Nordenskjold ice-foot glaciers. They are obviously built up from drift snow, and 

 have a definitely stratified structure (8). These ice-foot glaciers are what ARgTOWSKi 

 has described as slope glaciers {gehdngegletscher (9), and Gourdon as 'piedmont' 

 glaciers (10). 



" Upon the larger islands of Graham Land there are found thin bodies of inland 

 ice through which the rock peaks project as nunataks. This type of southern glacier, 

 resembling as it does some of the ice-caps of Spitsbergen, has been designated by 

 Otto Nordenskjold the Spitsbergen type." 



SOUTH ORKNEYS 



Whilst the local variations in type and character of the South Orkney glaciers 

 depend mainly upon topographical conditions, to which reference will be made 

 immediately, their main features are determined by the prevailing climatic conditions. 

 The climate of the Antarctic regions as a whole may be summed up as one where 



