NO. 1 



EMERY AND HOLSEMANN: SUBMARINE CANYONS 



shallow, with greatest errors in the narrowest part of the canyons (Fig. 

 2). In contrast, the average difference between wire and echo depths 

 for flat shelves and basin floors is less than about 3 meters. 



Fig. 1. — Index map showing areas which were sounded and 

 sampled off southern California, for which contours, 

 profiles, and sample positions are shown in Figures 3 

 through IS. 



H, Hueneme Canyon; M, Mugu Canyon; D, Dume 

 Canyon ; SM, Santa Monica Canyon ; R, Redondo 

 Canyon; SP, San Pedro Sea Valley; N, Newport 

 Canyon ; LJ, La Jolla Canyon ; Co, Coronado Can- 

 yon ; SCr, Santa Cruz Canyon ; SCa, Santa Catalina 

 Canyon; SCI, San Clemente "Rift Valley," T, Tan- 

 ner Canyon. 



Positions were determined at 5-minute intervals by a radar range 

 and bearing on a prominent coastal point, such as a pier end or a steep 

 cliff. Since the ship speed was 9 to 10 knots, positions are about 1.5 km 

 apart. 



