34 



Basin Slope 



Off most coasts the continents are surrounded by a 

 continental shelf and continental slope. The continental 

 slope forms the seaward margin of the continents from which 

 the water depth increases to the abyssal sea-floor several 

 thousand feet deep. Off southern California, however, the 

 continent is separated from the abyssal sea by a series of 

 basins and ridges. The slopes bordering these basins are 

 called ••basin slopes^* to distinguish them from true continen- 

 tal slopes. 



The basin slope in Santa Monica Bay is that part of the 

 sea floor seaward of the shelf and terminates on the floor 

 of the Santa Monica Basin. The average gradient is 5° sea- 

 ward of the outer shelf. The slope is broken into several 

 segments as a result of the two submarine canyons. West of 

 the outer shelf and south of Palos Verdes Hills, it is well- 

 defined, but south of Malibu and on the north side of Redondo 

 Canyon the basin slopes are partly the sides of submarine 

 canyons. Fathograms along the slope indicate a generally 

 smooth surface broken occasionally by small terraces or 

 steps. Profiles taken south of Malibu indicate that channels, 

 locally to 60 feet in depth are present. 



Santa Monica Basin 



A small part of the Santa Monica Basin can be seen in 

 the lower left corner of Fig, 5, The floor of the basin is 

 relatively flat but deepens slightly to the west. Shepard 

 and Emery (1941, p. 64) believe that there is evidence of a 



