20 DISCOVERY REPORTS 



between 90 and 120 W in the Pacific Ocean it lies in 70 S. The position suggests that 

 the boundary between the east and west winds does not lie in 6o° S as the available 

 meteorological data has indicated (Antarctic Pilot, 1930, pp. iii, 7), but as much as 5-10 

 farther south. This is in closer agreement with the ideas of Mossman, who states that the 

 boundary between the two winds is found in general near the Antarctic Circle (i9i8,p.2i). 



There are very few observations that give any information about the north and south 

 movements in the waters of the westerly current. The distribution of temperature, 

 salinity, and oxygen content in the coastal region is in agreement with the conclusion, 

 based on a consideration of the effect of wind and density differences, that there is a 

 rotary tendency in the current : the surface water is carried southwards and the deeper 

 water northwards. 



The current observations made at the winter station of the ' Gauss ' show that the 

 easterly wind sets up a surface current towards the south, and a deeper movement along 

 the coast towards the west-north-west (Drygalski, 1926, pp. 512-25). Drygalski con- 

 siders that the outer margin of the drift-ice, described by most observers as being com- 

 pact and only frayed out by certain winds for a limited time, is kept unbroken by the 

 movement of surface water towards the south. He also affirms that because of 

 the action of the surface current the belt of drift-ice substantially follows the 

 coast, and from its position inferences may be drawn as to the position of the coast-line 

 beyond it. 



The formation of the light surface water, especially in summer, near the Antarctic 

 Continent must, however, give rise to a northward movement from the region of the 

 westerly current to that of the easterly current. The effect of projecting land, submarine 

 ridges and ice-tongues will also lead to northerly movements which may carry water as 

 far north as the region of westerly winds. The greatest movement of this nature is the 

 northward current along the east coast of Graham Land ; others caused by the effect of 

 submarine ridges are found near the Kerguelen-Gaussberg ridge and the Shackleton 

 ice-shelf in the Indian Ocean, and on a smaller scale near Peter 1st Island in the Pacific 

 Ocean. The effect of projecting ice-tongues causing a smaller deflection to the north has 

 been noted by Drygalski (1926, p. 513) and by Davis (1919, p. 158). 



In the westerly current the northward movement is probably strongest in the lower 

 stratum of the surface layer, but the northward movement of drifting ice frequently 

 suggests that it also exists at the surface. The northward flow of water from the 

 region of the westerly current to that of the easterly current near the Kerguelen- 

 Gaussberg ridge and Peter 1st Island is marked by a northward extension of the 

 ice-edge to the east of these localities. 



THE ANTARCTIC CONVERGENCE 



South of 50 S, in the northern part of the Antarctic Zone, current observations are 

 few and scattered, but combined with evidence obtained from an examination of the 

 movements of drifting ice they show that the principal movement of the surface water is 



