ANTARCTIC OCEANOGRAPHY 279 



Tides 



On tides there are relatively few observations, a circumstance 

 which is probably due to difficulties arising from the ice. Otto Nor- 

 denskjold^^ reports a number of observations from Weddell Sea, 

 without, however, being able to deduce definite results. More im- 

 portant is the work of G. H. Darwin^" on the tidal observations of the 

 Scotia expedition on Laurie Island in the South Orkneys and of the 

 Discovery expedition in Ross Sea. R. E. Godfroy^^ has communicated 

 the observations of the second French expedition under Charcot at 

 Cape Horn, at the South Orkneys, the South Shetlands, and on the 

 west side of Graham Land; A. T. Doodson^^ those of the Terra Nova 

 at Cape Evans in Ross Sea; and K. Hessen^^ those of the German 

 Antarctic Expedition in the shelf sea north of Gaussberg. The ob- 

 servations of this last expedition have been characterized as the most 

 complete and the least affected by disturbing influences. In the 

 working up of the Scotia observations G. H. Darwin at his two sta- 

 tions finds a good correspondence with the equilibrium theory; K. 

 Hessen, however, at the Gauss station finds a marked spring-tide 

 lag as well as a constantly increasing preponderance of the diurnal 

 tides poleward. This last Darwin had also been able to establish for 

 Ross Island. Of course, further observations are greatly to be de- 

 sired, especially as we now know that tidal currents affect the sea 

 at all depths and thus interfere with the current system previously 

 discussed. For the Gauss station K. Hessen has been able to separate 

 the tidal currents from the wind-driven surface currents. 



Bottom Deposits 



All Antarctic expeditions have reported on bottom sediments 

 and concur in the statement that the Antarctic land mass is every- 

 where surrounded by deposits of a continental character, as Sir John 

 Murray had already declared after the return of the Challenger expe- 

 dition. From this fact he had concluded that the land of the Ant- 

 arctic is a continent and not an archipelago. These deposits, how- 



1' Nordenskjold, op. ciU, pp. 27-28. 



20 G. H. Darwin: Tidal Observations Made During the Voyage of the Scotia, 1 902-1 904 (Scottish 

 National Antarctic Expedition: Report on the Scientific Results of the Voyage of S. Y. "Scotia" 

 During the Years 1902, 1903, and 1904, under the Leadership of William S. Bruce, 6 vols.. The Scottish 

 Oceanographical Laboratory, Edinburgh, 1907-1920), Vol. 2: Physics, pp. 321-324. 



idem: Tidal Observations of the "Discovery," in: National Antarctic Expedition 1901-1904: 

 Physical Observations with Discussions by Various Authors, Prepared under the Superintendence of 

 the Royal Society, London, 1908, pp. 3-12. 



F. J. Selby, J. de Graaff Hunter, and G. H. Darwin: Tidal Observations of the "Scotia," 1902- 

 1904, ihid., pp. 13-16. 



21 R. E. Godfroy: Etude sur les marees (Deuxieme Expedition Antarctique Francaise 1908-1910, 

 commandee par leDr. Jean Charcot: Sciences physiques. Documents scientifiques), Paris, 191 2. 



22 British (Terra Nova) Antarctic Expedition 1910-1913. Miscellaneous Data, compiled by H. G. 

 Lyons, London, 1924, pp. 68-73. 



2^ Hessen, work cited above in footnote 15. 



