330 



The Geotectonic Factor 



Fig. 143. The Bering Bridge. Above, its present location, the Bering-Chukchi 

 platform. Below, its state of emergence when the sea level was at various 

 depths below the present level, (a), 75 feet; (b), 120 feet; (c), 150 feet; and 

 (d), 300 feet. (From Hopkins.) 



