This extensive ice-free area may have been formed by 

 the diversion of plateau ice, because of surrounding rugged 

 terrain, so that only stagnant ice remained over Bungar's 

 Oasis. It is unlikely that thermally heated waters have played 

 any part in producing the oasis. Presumably, meteorological 

 conditions have been mild and the heat intake has been suf- 

 ficient to waste away stagnant ice, thus producing an ice-free 

 area when there was no replenishment of polar ice. Low pre- 

 cipitation, catabatic winds, close proximity to the ocean, and 

 dark country rock with low albedo probably now contribute 

 to maintain warmth in the area. The freezing of the lakes 

 only at the surface and the heating of the water during the 

 summer and then the sinking of this heated water into the 

 lake must provide an additional heat reservoir. That the 

 long summer day is sufficiently warm to melt banks of snow 

 and ice deposited during the previous winter is suggested by 

 the reported air temperature of 36 degrees F. when the air- 

 craft landed. Also, the presence of many small lakes in the 

 depressions of the surrounding plateau ice is indicative of 

 extensive melting in this region. It is likely that the entire 

 Indian Ocean coastal sector of the Antarctic Continent would 

 be largely ice-free if it were not for the constant replenish- 

 ment of ice from the polar plateau. 



FIGURE 34. Oblique air photo of Bungar's Oasis showing contact of ice-free area with the surrounding 

 ice plateau. Note the two large black dikes traversing the country rock. 



65 



