accretion over the study period was 118 m 3 /m. Table U summarized the above 

 NGVD , below NGVD , and total profile volume changes between profiles. This net 

 accretional trend may have been a result of longshore transport of sand into 

 the FRF coastal area. The migration of sand waves has been identified along 

 the Outer Banks coast (Dolan 1971) , and the relationship of the beach with 

 rhythmic crescentic bars has been noted (see Komar 1976 and Davis 1985 for 

 further discussion) . This sand wave/crescentic bar migration process is a 

 three-dimensional process and is beyond the scope of the present two- 

 dimensional data set. 



28. High wave events (waves greater than 2 m) and storm events (wave 

 power greater than 50 kW/m) have been plotted on Figure 9 to show the rough 

 correlation of high wave events with net erosion of the profile. However, net 

 accretion was also measured under some high wave events. Because of the 

 irregular spacing of the profile collection, most high wave events were not 

 closely bracketed, and some recovery was possible before the next profile. 



29. The nearshore bar should be a good indicator of the response of the 

 profile to wave events. Figure 10 shows the correlation of the time series of 

 wave power and wave steepness with bar crest position measured on the profile 

 seaward of the baseline. The berm crest position indicates the accretion and 

 erosion on the visible portion of the profile and is plotted, although there 

 is less dramatic changes than the inner bar. The trend is for erosion of the 

 berm to correspond to accretion in the nearshore, with seaward movement of the 

 inner bar crest. As the berm moves seaward during accretion, the bar moves 

 inshore. 



30. A correlation can be seen in Figure 10 between the movement of the 

 bar and berm and the wave parameters of wave power and to a lesser extent wave 

 steepness. The wave power is defined as: 



P = n E C 



where 



n„ = 1/2 for deep water 



E = deepwater wave energy given as 1/8 pg H„ 2 



C = deepwater wave celerity given as gT/2?r 



36 



