To North 



o 

 o. 



100 



50 







JT" 



™^ 



f f I 



Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct Nov. Dec. 



(Mo) 



Figure 63. Gross and net longshore transport rates 

 at Sea Isle City, obtained using the 

 energy flux method. 



Caldwell presented the following longshore transport values for Sea Isle City 

 in thousands of cubic yards per year: 



North 



South 



Gross 



Net 



500 



650 



1,150 



150 south 



Caldwell's net rate to the south is only 35 percent of the rate from this 

 study. This may be the result of using equation (4) in this analysis which is 

 83 percent higher than that previously recommended (U.S. Army, Corps of Engi- 

 neers, 1966) . 



b. Alongshore Sand Movement Above MSL . From 1962 to 1972 the beach sur- 

 veys indicated the movement of a sand mass (sand wave or hump) alongshore. On 

 individual profile lines (Fig. 41) the net volume change above MSL, averaged 

 yearly to remove seasonal effects, and the net yearly shoreline change (Fig. 

 40) followed definite trends through time. Periods of shoreline advance 



76 



