2 Inner Shelf Concepts 



Introduction 



This chapter reviews concepts that are crucial in determining the geo- 

 logic aspects of inner shelf cross-shore sediment transport. These con- 

 cepts include the equilibrium profile, the depth of closure, and the effect 

 of the geological framework on the equilibrium profile and cross-shore 

 sediment transport processes. These concepts are of concern to the engi- 

 neering and scientific community primarily due to the unquantifiable 

 amounts of sediment that are transported onshore and offshore of the inner 

 shelf. Additional references concerning these topics can be found under 

 individual reference lists entitled "Equilibrium Profile/Profile Adjustment 

 References" and "Depth of Closure References" in Appendix B. 



Equilibrium Profile 



The equilibrium profile was first defined by Fenneman (1902), who 

 stated "There is a profile of equilibrium which the water would ultimately 

 impart, if allowed to carry its work to completion." Additional equilib- 

 rium profile studies include those by Cornaglia (1889); Ippen and Eagle- 

 son (1955); Eagleson, Glenne, and Dracup (1961); and Zenkovich (1967), 

 who argued in terms of the null point hypothesis. This hypothesis states 

 that shoreward increases in wave orbital asymmetry should be counterbal- 

 anced by shoreward increases in bed slope, thus creating an equilibrium 

 profile. 



Studies at Mission Bay, California, and the Danish North Sea Coast by 

 Bruun (1954) found that the average of field profiles fits the relationship: 



h = Ay'^ (1) 



where 



h = water depth 



Chapter 2 Inner Shelf Concepts 



