^ 10 



c 

 a> 



Z 0.8 



i 0.6 

 o 



I 0.4 

 "5 0.2 - 



0.0 



I I I I II 



2 4 6 8 10 12 14 16 18 20 

 Profile Line 



Figure 69. Correlation coefficients 



calculated for the regression 

 curves shown in Figure 68 

 (shoreline change versus 

 volume change) . 



LudlaiD Beach Average 



^ 5 



-t- 



" 4 



3 



il 2 



1 1 



CO 



<3 <a oLi-J ' ' ' ' ' ' ' " I I I I I I II 



2 4 6 8 10 12 14 16 18 20 

 Profile Line 



Figure 70. Mean sand volume changes 

 above MSL which accompany 

 shoreline retreat or advance 

 along Ludlam Beach. 



a. Corson Inlet . Historically, the migration of Corson Inlet has varied 

 in direction and rate. From 1842 to 1955, the south shore of the inlet migrated 

 2,300 feet north, an average rate of 20 feet per year (Fig. 27); however, this 

 trend was not constant. Between 1842 and 1899, for example, the position of the 

 southern shore of the inlet remained nearly fixed. From 1949 to 1974 Corson 

 Inlet migrated south at a rate of 92 feet per year (Fig. 56), about 4.5 times 

 greater than the long-term northern migration trend, and the inlet width in- 

 creased 1,900 feet (Fig. 55) or 76 feet per year. Width changes during the 

 1949-74 interval were highly variable while the migration rate was nearly con- 

 stant. The change in position and width of the inlet was mostly due to erosion 

 of the southern shore of the inlet. The northern shore of the inlet accreted 

 and prograded south at 16 feet per year. 



87 



