244 



HEEZEN AND MENARD 



[chap. 12 



These deep gorges, cutting all the continental slopes of the world, vary from 

 less than a mile to ten miles in width, from a few fathoms to several hundred 

 fathoms in depth, and from a few miles to a few hundred miles in length 

 (Figs. 7 and 12). The slopes of the walls of submarine canyons are generally 



130 



40° 



39° 



38' 



37' 



36' 



35' 



34° 



MURRAY FRACTURE ZONE 



130" 



129° 



128° 



127" 



126° 



125° 



124° 



123° 



122° 



121° 



Fig. 12. Topography of Central California. Co^rter interval 20 fm below 1900 fm. Local 

 elevations indicated by pattern of dots. Note ranges of hills west of the Monterey 

 fan. (After Menard, 1960.) 



greater than the gradient of the continental slope. Some investigators (Menard, 

 1955) prefer to limit the term "submarine canyon" to that portion of each 

 feature which is incised into the continental slope, and to refer to that portion 

 of the same feature which cuts into the continental rise as a deep-sea cliannel . 

 Other investigators (Heezen et al., 1959 ; Ericson et al., 1951) prefer to refer to 

 the entire system as a "submarine canyon", regardless of the fact that the size 

 of the feature sharply decreases on the lower gradients of the continental rise. 



