HYDROLOGY OF THE BRANSFIELD STRAIT 



35 



pack-ice in this area in the spring of 1930 than in November 1929. Thus in December 

 1930 the open water was left more saline before subsequent dilution by ice melting 

 occurred. The vertical sections, Figs. 42-4, on the line from between Elephant and 

 Clarence Islands towards Joinville Island, show the isolines sloping up towards St. 541, 

 the nearest station to Joinville Island that could be worked. St. 541 is situated on the 

 broad continental shelf north-east of Joinville Island, and the water here, throughout 

 the whole vertical column, has been completely mixed and consists of Antarctic surface 

 water of Weddell Sea origin. In this section the presence of warm deep water in traces 

 is indicated by the slight inversions of temperature which occur at all stations on this 

 line except in the completely mixed water at St. 541. Sts. 538 and 540 show two 

 temperature inversions at different depths ; the intermediate maximum temperature at 

 the greater depth of St. 540 occurs at a depth of 500 m., which is within 10 m. of the 



544 545 



STATION 542 543 



C.MELVILLE king george 



500m 



1000., 



1500., 



34£0£_! 



547 



34-53%,TRINITY PENIN* 



2000n 

 Fig. 45. Vertical section of salinity : C. Melville, King George Island, to Trinity Peninsula, December 1930. 



sea-bottom. Thus at this station the bottom water itself contains an admixture of warm 

 deep water. The increase in salinity with depth and the presence of temperature 

 inversions show a stable layering at all stations in this line, except at St. 541 where the 

 whole column is practically homohaline. 



The vertical sections of the line from Cape Melville to Trinity Peninsula, Figs. 45-7, 

 show as usual the increase of salinity and decrease of temperature in the surface water 

 as the line progresses towards the coast of Trinity Peninsula, except at St. 543, some 

 15 miles from Cape Melville. At this station the current is flowing more to the north, 

 and positive temperatures are found in the first 30 m. The greatest increase in surface 

 salinity occurs between Sts. 545 and 546. At the latter station the 0-400 m. layer is 

 practically homohaline, whilst the uppermost portion of the layer has been warmed by 

 insolation. At St. 547 the whole vertical column, consisting of Antarctic surface water, 



5-2 



