SECT. 2] 



CONTINENTAL SHELF AND SLOPE 



289 



longitudinal ridges or seamounts, occurring principally at 700 fm. Only two 

 profiles, off Lofoten Islands and off Tromso, include no important break of 

 slope below the continental shelf. The most irregular profile lies off the southern 

 tip of Spitzbergen. Other areas including seamounts on the slope are found off 

 San Francisco, California (Fig. 7), off Nantucket Island, New England and 

 elsewhere. 



37° N 



Fig. 7. Continental shelf and slope off San Francisco, California, with canyons and large 

 seamounts on the lower slope. Contour interval 300 ft. (After Shepard and Emery, 

 1941.) 



The Russian expeditions to East Antarctica (Jivago and Lissitzin, 1957- 

 1958) have discovered that the slope off this continent displays a wide variety 

 of types. In front of the Shackleton ice shelf (96°-100°E), and off the Princess 

 Ragnhild Coast (25°-30°E), the slope consists of tilted plains down to 800 fm 

 or more. Off Llitzow-Holm Bay (38°E), and to the south of the Kerguelen- 

 Gaussberg Ridge, it is often made up of tilted plains with gentle undulations. 

 Steps or benches of moderate slope alternate with steep and short scarps in 



