60 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



20 



UJ 40 



UJ 



60 



80 



90 



10 



20 



en 

 t-ioo 



UJ 



200 



STATUTE MILES 

 4 6 8 



10 



12 



20 



40 



60 



80 



90 



STATUTE MILES 

 10 15 



20 



25 

 



10 



20 



30 



40 



Figure 15. — Characteristic bottom profiles of inshore zone, continental shelf, north half, Gulf of Mexico. Steepening 

 and progressive smoothing of bottom from profile to profile correlates with increasing energy of water, decreasing 

 resistance of bottom, and increasing steepness of initial drowned surfaces. The theoretical low-energy, breakerless 

 profile of Keulegan and Krumbein (curve 7) is compared with a beachless sector of drowned karst coast off Florida 

 (curve 6). Profiles are listed on pages 59 and 60. Sectors are described in tabulation, pages 61 and 62. The shore- 

 face extends 1 to 4 miles offshore. The ramp extends out from the shoreface as far as the profile continues to flatten. 

 The outer parts of profiles 1 and 2 are averaged between the points shown. 



Bottom "hard," mostly oolite limestone. Little 

 sand reported in region. Beachless. 



(6) Off rocky coast of Florida at Net Spread 

 Key between Chassahowitzka and Weekiwachee 

 Rivers, 28°38', 82°40'. Chart 1258, 1944 edition. 

 Beachless. Hard bottom (limestone). Very few 

 notes of sand in region. 



(7) Theoretical mathematical curve of Keulegan 

 and Krumbein (1949) for the steepest bottom 

 across which waves will move with the maximum 

 height without breaking. A wave 3 m. high 

 enters the shelf-sea on a bottom 4 m. deep 40 

 km. from shore. Depth equals the 4/7 power of 

 the distance from shore. A hyperbolic curve. 



