820 



BIOLOGY OF THE SEAS OF THE U.S.S.R. 



The distribution of soils on the floor of the Sea gives a clear and simple 

 picture (Fig. 411). Large areas of the floor of the northeastern half of the 

 eastern shelf zone and the western half of the Bay of Anadyr are occupied 

 by sands. Sand forms a wide band stretching southwards to Cape Olyutorsky. 

 The rest of the shelf zone and the elevations of the Olyutorsky and Southern 

 ridges have a siltstone bed with a large patch of siltstone-clay ooze. Siltstone- 

 clay diatomaceous ooze with large patches of clay diatomaceous ooze in 

 each trench occupy the deep bed of the Sea. 



The Soviet coast of the Bering Sea is more than 5,000 km long. Steep 



Fig. 411. Bottom soils of Bering Sea (Lisitzin). 1 Boulders-shingle-gravel; 2 Sands; 



3 Aleurites; 4 Aleurite-clay-diatomaceous oozes; 5 Clay-diatomaceous oozes; 



6 Aleurite-clay oozes without silica ; 7 Outcrop of rock. 



shores and the small tidal range limit the width of the beaches, and the 

 development of the littoral fauna is restricted by the severe winter conditions 

 and the presence of ice. 



A diagram of the circulation of surface waters of the Bering Sea shows a 

 large cyclonic movement (Fig. 412). 



The entry of surface and deep Pacific Ocean waters through the straits be- 

 tween the Aleutian Islands is the main feature of the system of Bering Sea 

 currents. The water masses move northward along the eastern side of the Sea 

 creating several anticyclonic and cyclonic rotations on the eastern side, and a 

 circular cyclonic current on the west. Skirting St Lawrence Island on the east, 

 Pacific waters enter the Chukotsk Sea through the Bering Strait, warming its 



