13 



General Characteristics of the Far Eastern Seas and of 

 Adjacent Parts of the Pacific Ocean 



I. GENERAL CHARACTERISTICS 



A quarter of the coast of the u.s.s.r. is washed by the Pacific Ocean and the 

 Seas of the Far East. Only a seventh of the whole coast is actually washed by 

 the waters of the Pacific, while six-sevenths of it consists of the shores of the 

 Seas of Japan and of Okhotsk and the Bering Sea. [The total area of the three 

 Seas (4,872,000 km 2 ) is almost double the area of the European Seas of the 

 u.s.s.r. from the White and Barents Seas to the Aral Sea (2,842,500 km 2 ). 

 The volume of the Far Eastern Seas (6,741,300 km 3 ) is seven times greater 

 than that of the European Seas (978,300 km 3 )]. 



There is a free exchange of water through the numerous straits between 

 the three Seas and the Pacific. The whole mass of water of the Bering Sea has 

 free access to the Pacific through its many deep straits (down to 5,000 km), 

 and therefore it can be considered as a bay of the Ocean. This is true to a 

 lesser extent of the Sea of Okhotsk since, apart from its surface and modified 

 near-bottom layers, its waters have the same characteristics as those of the 

 neighbouring Pacific. 



The Sea of Japan is the most isolated from the Pacific, owing to the shallow- 

 ness (not more than 130 m) of the four straits which connect them. 



The Sea of Japan has not, however, a reduced salinity ; as a whole this 

 approximates to that of the Ocean ; its depths are well supplied with oxygen 

 as a re.sult of considerable mixing in winter. 



A small shelf and great depths are characteristic of our Far Eastern Seas. 

 Only the northern and northeastern parts of the Bering Sea are occupied by 

 vast shallows, which constitute about half of its whole area. The shelf zone is 

 very narrow in the Sea of Okhotsk and narrower still in the Sea of Japan. This 

 influences the composition and especially the biological properties of its fauna. 



The Seas of Japan and Okhotsk and the Bering Sea extend in a southwestern 

 and northeasterly direction for almost 5,000 km. Whereas the climate of the 

 northern parts of the Sea of Okhotsk and of the northwestern parts of the 

 Bering Sea is arctic and severe, and both contain large masses of ice for several 

 months, the small Kuril Bar and the southern part of the Sea of Japan closely 

 approach the tropical zone. In the northwesterly part of the Pacific, as also 

 in that of the Atlantic, the cold and warm water zones occur very close to 

 each other, and as a result masses of cold water move from the north and 

 masses of warm water move from the south (Gulf Stream, Kuroshio). This 

 is in contrast to the northeastern sides of the oceans, where the extent of these 

 zones is considerably greater, and the boundaries between the cold, temperate 

 and warm water zones are spread out and the sharpness of the division be- 

 tween them is less distinct (Fig. 319). 



As a result of the convergence of the cold and warm waters on the western 



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