METEOROLOGY OF AMERICAN ANTARCTIC 313 



As for the depressions themselves, the rather sketchy pressure 

 maps that it is possible to construct with the small number of simul- 

 taneous observations available show that they are generally closed 

 depressions and that they follow a trajectory broadly moving from 

 west to east between Tierra del Fuego and the South Shetland 

 Islands. Sometimes they pass to the north, sometimes to the south of 

 the South Orkneys. When, on coming from Bellingshausen Sea, they 

 strike against the high mountains of Graham Land, they seem to stop 

 and sometimes to turn on their tracks as if to look for a direct passage. 

 This they finally find either to the north through Drake Strait or 

 perhaps to the south through some still unknown lowland or other 

 depression in that region. 



These trajectories of the atmospheric cyclones, in the Antarctic as 

 in the temperate regions, are very complex and doubtless often describe 

 pronounced curves or even loops, influenced as they are by the always 

 changing distribution of ice cover and open sea. 



