vicinity of Kotzebue Sound (figs. 6L and 6M) indicates the 

 presence of stony bottom. Elsewhere, the bottom is smooth 

 and probably fine-grained. (The irregular appearance of 

 the bottom trace in other parts of figure 6 is due to irregu- 

 larity of the outgoing sound signal.) 



A notable feature of the Chukchi shelf is the shallow 

 basin lying between Bering Strait and Herald Shoal; the deepest 

 part of this basin is about 34 fathoms, or about 7 fathoms 

 below the surrounding shelf. Herald Shoal rises to 7 fathoms 

 and is the shoalest part of a large swell rising from about 

 20 fathoms. 



The position of the margin of the shelf in the Chukchi Sea 

 is not known, as the polar ice pack has prevented penetration 

 and the obtaining of soundings much further north than about 

 73°N. North of Point Barrow the shelf narrows to 30 miles, 

 and the deep Arctic Basin, where soundings up to 1333 fathoms 

 have been recorded, lies near shore. 





Figure 6. Fathogram of the Chukchi Sea showing the remarkably level and shoal bottom (see fig. 1 for geographic location of the 

 strips). Add 3.7 fathoms to indicated depths. 



