V 



-138,500 



_ 100,000 



1— 



[V 







o 



■D 



-^ 8 0,000 



> 



1 



1 



-1 



1 



1 Total Volume Moving Alongshore 



1 60,000 



■ L-<r 









Groins 





•=1 40,000 



c 



1 20,00 







£ 





Figure 64, 



) 5,000 10,000 15,000 20,000 25,000 



Distance South of Corson Inlet (ft) 



Volume moving in an alongshore sand wave, showing 



a significant decrease south of Corson Inlet. 



shoal closes, and a large quantity of material is transferred at one time to 

 the downdrift barrier island. Bruun states this rapid accumulation substitutes 

 several years of downdrift accumulation by normal inlet sand-bypassing processes. 



The March 1962 storm could have caused such an accumulation at Strathmere. 

 As shown in Figure 62, about 0.05 square mile of new land was created at the 

 south shore of Corson Inlet in March 1962. This change, which amounts to 

 186,000 cubic yards of accretion above MSL when assuming a 3.6-foot land ele- 

 vation (Fig. 17, berm elevation), is opposite of the general trend of a net loss 

 of land south of the inlet. In 1962, land-area gains north of the inlet were 

 average but the inlet shoal area (Fig. 62) decreased significantly, suggesting 

 a source there. The movement of the channel during the storm (Figs. 55, 56, 58, 

 59, and 60) did not appear to occur as at Matanzas Inlet. 



c. Alongshore Variation in Sediment Transport . It cannot be assumed that 

 wave energy reaching the coast is uniform the length of Ludlam Beach, nor that 

 the wave approach direction is constant along the coast. Information on wave 

 approach direction is available, based on aerial photo analyses. Wave approach 

 direction at breaking for 20 synoptic times along the beach is given in Figure 

 51. The figure mostly represents conditions in the spring and statistically 

 cannot be indicative of the average yearly condition of wave approach direction. 



78 



