HYDROLOGY OF THE BRANSFIELD STRAIT 63 



south-east before returning to the north-west and then flows north-east past the South 

 Shetland Islands. 



4. Charts of dynamic topography were constructed according to a new method of 

 Professor Helland-Hansen. By combining the hydrographic results of November 1929 

 and December 1930 in these charts the two chief currents and in particular the Weddell 

 Sea influence in the strait were demonstrated. Charts showing the movement of water 

 at the levels of o, 50, 100, 200, 300, 400 and 600 m. are given for February 1929, 

 November 1929 and December 1930, the two latter being combined. In February 1929 

 the characteristic bend of the lines of flow of the surface water on the line from Living- 

 ston Island extend almost as far across the strait as Astrolabe Island, whereas in 

 November of the same year the south-easterly movement did not reach so far. In 

 February 1929 the north-easterly current was concentrated about 10 miles from King 

 George Island over a very narrow path, in contrast with the widespread nature of this 

 current in November 1929. At depths below 200 m. the water movements in February 

 1929 differed from those in November of the same year in that the predominant move- 

 ment appeared from the east in the former month. The results for December 1930 

 showed in particular the great influence of the Weddell Sea at the north-eastern end of 

 the strait. 



5. The temperature of the Antarctic bottom water inside the strait is much lower 

 and the salinity slightly less than outside the strait. The Bransfield Strait Antarctic 

 bottom water is formed in situ as a result of freezing processes in winter on the wide 

 continental shelf of western Graham Land and Trinity Peninsula. This bottom water 

 has a very high oxygen content which indicates its recent renewal. 



6. No attempt at discussion of seasonal variation has been made owing to lack of 

 suitable data, but the differences in temperature and salinity along a line of stations at 

 the north-eastern end of the strait in February and November 1929 are discussed. 



7. A note is added on variable movements of pack-ice in the strait and on currents 

 between the South Shetland Islands. 



In conclusion the author would like to express to Professor B. Helland-Hansen, 

 Director of the Geophysical Institute, Bergen, Norway, his very great appreciation of 

 the kindly help and advice given him throughout the preparation of this report and for 

 valuable criticism of the manuscript. 



