THE HEART OF THE ANTARCTIC 



are directed towards the west-south-west, the quarter from 

 which of course the prevalent wind blows. 



Our actual experience of a heavy blizzard, at a level 

 of over 5000 ft. on Erebus, as well as our subsequent 

 observations of the height to which the blizzard wind ex- 

 tended, showed that during blizzards the whole atmosphere 

 from sea-level up to at least 11,000 ft, moves, near Cape 

 Royds, from south-east to north-west, and the speed of 

 movement is from forty up to over sixty miles an hour. 



HEIGHT IN FEET ABOVE SEA LEVEL 



5500^ 8500"" lOGSO" 11300" 



13300*^ 



- 5- 

 10* 

 15* 



20° 

 25- 



"Vfape Royds ' j ' ' 1 







1 , in 





f , • S 





1 H 





1 .1 Ul 





1 1 ^ 



1 1 . _ . „.. o 



















h 

 z 



Ld 



oc 

 I 



Ui • 



111 

 111 

 on 

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 Id 

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The Curve of Atmospheric Temperature from Cape Royds to Summit of Erebus 



The day that we reached the summit of Erebus, March 10, 

 1908, we found ourselves at the level of over 13,000 ft. 

 within the lower limit of the upper wind. Subsequent 

 observations by us of the point in the steam-cloud over 

 Erebus, where the bend took place at the junction of the 

 lower limit of this current, with the top limit of the middle 

 current, showed that after and during the blizzard the 

 middle-air current, normally blowing from the west-south- 

 west, is temporarily abolished, being absorbed by the 

 immense outrushing air stream of the south-east blizzard. 

 We noticed that usually in winter time, especially when 

 a blizzard was impending, strong cloud radiants were 



408 



