HYDROLOGY OF THE BRANSFIELD STRAIT 55 



little flow is shown coming from the south-west except close to the South Shetland 

 Islands, and the movement from the east end of the strait appears to predominate. This 

 would account for the entire absence of any intermediate temperature maximum at all 

 stations along the line from Livingston Island in February, except at St. WS 393, which 

 is nearest to the South Shetland group and owes its positive temperatures between 

 100 and 300 m. to water from the south-west. In the discussion of the vertical sections 

 of temperature and salinity attention was drawn to the great difference in the tempera- 

 ture-salinity diagrams of Sts. WS 393 and WS 392. 



APRIL 1927 



A discussion of the water movements in April 1927 is rendered extremely difficult by 

 the conflicting observations on the line from King George Island to Trinity Peninsula. 

 Attention has already been drawn to the fact that several salinities are abnormally high, 

 probably due to the partial freezing of the sea water in the water bottles before a sample 

 was withdrawn. The observations were made in very unfavourable conditions and it 

 is probable that some of them are unreliable. When the vertical section of the anomaly 

 of specific volume was constructed the salinity and temperature curves were smoothed, 

 but the result as shown in the topographic charts is not happy. The levels of the 

 various surfaces at St. 197 as shown in the charts are too low and those at St. 198 

 too high, with the consequence that the dynamic isobaths show a large whirl at all 

 depths at St. 198. This is not at all likely in view of the results from other years. 

 The characteristic bend of the dynamic isobaths along the line from Livingston Island 

 which was noted in both of the surveys in 1929 is once more shown by the observations 

 in 1927. For this season one chart only, that of the surface movements, is reproduced 

 (Fig. 66). 



It must again be stressed that in the absence of more complete data the movements of 

 water as outlined above are to be regarded as purely tentative. It is recognized that the 

 dynamic isobaths could have been drawn in other ways, and it is possible that future 

 work will considerably modify the directions of the flow which have been deduced. 



THE DIFFERENCES IN TEMPERATURE AND SALINITY 

 IN FEBRUARY AND NOVEMBER 1929 ALONG THE NORTH- 

 EASTERN LINE OF STATIONS 



Two hydrological surveys were made in 1929 : one in February when typical summer 

 conditions were noted, and the other in November which reflected late winter or early 

 spring conditions. It has already been noted in the discussion on water movement that 

 the chief differences in these two surveys occurred at the north-eastern end of the strait. 

 For this reason it was thought that a comparison of the observations in February and 

 November at stations which were as nearly as possible in the same position on the line 

 from King George Island would be of interest. The stations which are available are the 



