Figure 3. Seasonal directionality of offshore wave 

 conditions near Charleston, SC (USACE 1974) 



Net rate of littoral drift was estimated to be 128,000 cu m/year at Murrells 

 Inlet (Kana 1977); 290,000 cu m/year at Bull Island (Knoth and Nummedal 1977); 

 130,000 cu m/year at Capers Island (Kana 1977); and 200,000 cu m/year at 

 Charleston (FitzGerald, Fico, and Hayes 1979). 



12. Hubbard, Barwis , and Nummedal (1977) and Nummedal et al. (1977) 

 noted wave energy flux for South Carolina and the South Atlantic coast of the 

 United States decreased from north to south. Wave energy flux, the amount of 

 energy expended by a wave per unit distance per unit time, is related to wave 

 period and the square of wave height. Height and period data for the study 

 area were obtained from the Phase III, USACE, Wave Information Study (WIS) 

 (Jensen 1983) , which contains inner shelf wave statistics hindcast from a 

 20-year period of meteorological data (1956-1975) at an along-the-coast inter- 

 val of 16 km. Average significant wave height, maximum significant wave 

 height, and average period were plotted from WIS data and show alongshore 

 variation within the study area (Figures 4 and 5) . Wave height and period 



14 



