^ n c 



T I C 







"^'^ 



*' i->^.'^'~^ 



// 



Figure 2-24. — Length of rivers in U. S. S. R. 



of Murmansk is almost ice-free, while Archangel (Arkhangelsk) 

 on the White Sea is frozen for 140 days. This is an important 

 factor in the northern sea route. 



PHYSIOGRAPHy 



In general the arctic and subarctic regions of the Soviet Union 

 can be divided into five physiographic provinces. The coastal 

 plains described above are the tundra area. Between the Soviet 

 or western part of these plains and the Siberian part lie the Urals 

 and the extensive west Siberian plain, drained by the Ob and the 

 Taz. East of the Yenisei is the central Siberian plateau. This 

 is an area of crystalline rock extending to the Lena River. The 

 three Tunguska rivers dissect the southern and western part of 

 the plateau. The upland regions rise to over 3,000 feet in some 

 places. East of the plateau is the region of the Siberian ranges, 

 an area of rough dnd broken terrain, partially glaciated, and reach- 

 ing to heights over 9.000 feet. 



A physical map of the Soviet shows the predominance of two 

 features: the vast plains and the long rivers. The rivers which 

 drain the arctic and subarctic regions are very long. The Yenisei 

 System is over 3,500 miles in length, the Lena 2,700 miles, the 

 Ob 2,500 



78 



