6o 



DISCOVERY REPORTS 



made by the 'Gauss', 'Valdivia' and 'Planet' have been used in addition to our own 



data. 



Where the water from the Agulhas current meets the West Wind Drift there is a 

 region of very irregular currents, and streams of warm highly saline subtropical water 

 alternate with areas of colder and less saline sub-Antarctic water. The existence of such 

 isolated streams of subtropical water illustrates the tendency of the subtropical water 

 to spread southwards over the sub-Antarctic water, and to remain at the surface 

 rather than sink at the convergence. 



A typical record of the surface temperature across this region, obtained on a passage 

 from Cape Town to Bouvet Island in October 1930, (Station List, 1932), is shown in 

 Fig. 15. The principal boundary between the subtropical and sub- Antarctic waters lies 

 just north of St. 449, but there is another area of sub-Antarctic water 1-2 farther north 



"HURgSDAY 





a * 



-i-i i-L-L 



FRlgDAY k 



at- ■ V * — -*- 



SaTU°RDAY 



» * * 



SunSday k 



■ t=P=F 



T-J— '"-r= rp-T™ —;. ._ -i.-.t. i~f~ 



fct±±2^ 



36°0OS 

 16*20' E 



3SfOO'S 

 I6°I0'E 



42°00'5; 

 )5°2CTE. 



—145° 00 S 



Fig. 15. A continuous record of the surface temperature between 35 and 46 S. on a passage from Cape 



Town to Bouvet Island, October 1930. 



and a region of mixed water in between. There is also an outlying stream of subtropical 

 water at St. 450. Such outlying streams sometimes have a depth of 300-400 m., as at 

 St. 450, but frequently they are confined to a shallow surface stratum of only about 

 80 m., as at St. 431 (ibid.) and St. 1165 (section 7, Plates X-XII). The deeper currents 

 are probably relatively stable features and are likely to be united to the main body of 

 subtropical water farther north, but the shallow streams may be only short-lived and 

 isolated. 



South-east of the Cape of Good Hope the convergence is crossed by section 8 

 (Plates XIII-XV) in 43 50' S, 25 40' E; the temperature falls from 15-5 to io° C, 

 and the salinity from 35-2 to 34-6 °/ 00 in about 9 miles. A similar drop of temperature 

 was observed by Brennecke (1909, p. in) between 41 35' S, 22 10' E, and 42 42' S, 



