262 POLAR PROBLEMS 



above 6000 feet. Around the pole itself the plateau surface is uni- 

 formly over 10,000 feet above sea level. 



In its accumulation the ice has piled up on the land to a height 

 which represents, for the time being, equilibrium between precipita- 

 tion and wastage — the latter effected both by surface ablation and 

 slow glacier flow of the ice to the periphery of the continent. Under 

 the regime of an ice age such as that prevailing in Antarctica today 

 there is no knowing how high the heaping up of the ice over the land 

 may extend. Possibly at some spot eccentric to the pole the ice dome 

 may exceed the 10,000 feet registered at the pole. This is rendered 

 the more probable on account of the pole itself being eccentrically 

 placed in relation to the general build of the land. But counteracting 

 the effect of this eccentricity is the fact that the rocky ranges along 

 the fault scarp, between the pole and the Ross Sea depression, are 

 reported to reach elevations up to 15,000 feet. They therefore must 

 be effective in damming back the ice of the plateau in the neighborhood 

 of the pole. 



The determination of the contour of the ice cap is not merely of 

 interest to the geographer and glaciologist but is of very considerable 

 importance to the meteorologist.^^ The latter finds in it a prime factor 

 in the determination of the flow of local surface winds, which, in turn, 

 are responsible for currents in the neighboring seas and the movements 

 of the pack ice. 



Determination of the Thickness of the Ice Cap and Delineation 

 OF THE Underlying Rock Floor 



Having determined the contour of the surface of the inland ice 

 sheet, there is next the problem as to the thickness of this ice cap and 

 the delineation of the underlying rock floor. Here is a problem of the 

 greatest possible interest and importance. We want to determine the 

 topographical features of the buried rocky land, to ascertain what 

 valleys, what mountain peaks — in short, what physiographic relief 

 is smothered under the ice. Once this is outhned, we shall be in pos- 

 session of a wealth of information relating to the preglacial history of 

 that land; also, we shall know more about the modifying effects of 

 ice-cap erosion and shall have secured the long-sought data as to the 

 thickness attained by such continental ice caps; finally, the question 

 will be answered as to whether there is a rocky continent or merely 

 an island archipelago underlying the ice carapace. 



Such an undertaking is certainly an ambitious project but should 

 be well within the realm of possible accomplishment. What is required 

 is that some method be devised to sound the depths of the ice. Sev- 

 eral years ago when echo-recording instruments had been perfected in 



" W. H. Hobbs: The Glacial Anticyclones: The Poles of the Atmospheric Circulation, Univ. of 

 Michigan Studies: Sci. Ser., Vol. 4, New York, 1926. 



