HYPSOGRAPHIC CURVE SHOWING THE AREA OF THE EARTH'S SOLID 

 SURFACE ABOVE ANY GIVEN LEVEL OF ELEVATION OR DEPTH. 



AREA OF EARTH'S SURFACE IN 10® KM* 

 12 3 4 



■U+30,000 



t- 

 ui 



UJ 



u. 



— +20,000 H 



< 



+10,000 ^ 



-I 

 u 



10,000 



111 

 ■1. 



-20,000 z 



-30,000 



I- 



0. 

 UJ 



o 



(The smooth curve represents the cumulative summation of areas denoted by shaded 'barB.) 



139 



