-36,000 sq m/year. The land region included in the analysis extended 8 km 

 north and 8 km south of the inlet as it existed in 1849 (Figure 37). The net 

 loss for the total system, which may include some effects of New Inlet, re- 

 sulted from shoreline retreat adjacent to the inlet; this probably represents 

 a transfer of sand from the ocean shoreline region to the sound by inlet cur- 

 rents. Note that the decrease in plan area was continuous south of the inlet 

 but the variable plan area changed north of the inlet. The increase to the 

 north occurred as the result of a spit which built south as the inlet migrated 

 south. 

 Cape Hatteras and Cape Henry 



88. The land protrusion of Cape Hatteras (Figure 2) has changed sig- 

 nificantly in plan area and shape since the first survey in 1852 (Figure 41). 

 Figure 42 shows that a decrease in land area occurred as the east-facing coast 

 retreated (eroded) to the west and the south-facing coast prograded (accreted). 

 Figure 28 shows evidence of the ocean shoreline retreat at the Cape Hatteras 

 lighthouse. In 1870, when the lighthouse was built, the shoreline was 600 m 

 east of its 1980 position. Retreat has been continuous except for a brief 

 period in the 1940 's where a slight progradation occurred. Figure 43 shows 

 that Cape Point moved about 0.5 km in a net southwesterly direction between 

 1852 and 1980. The figure also shows that Cape Point fluctuated greatly in 

 position during that period and that the present position is likely a tempo- 

 rary site. 



89. Cape Henry, during the same period, changed in a different way 

 (Figure 44). The east-facing shore moved east (prograded), while the 

 north-facing Chesapeake Bay shore moved south (eroded). The changes at Cape 

 Henry were nearly an order of magnitude smaller than the changes at Cape 

 Hatteras. 



Variations in shoreline change rates with time 



90. Shoreline change rates varied greatly with time. The extent of 



this variation is illustrated in Tables 11 and 12. The periods shown on the 



tables, 1852-1917, 1917-1949, and 1949-1980, are expedients based on available 



survey data. The shoreline change data, when averaged by reach (Figures 45 



and 46) suggest these trends: 



a. Shoreline retreat on the east-facing ocean coast was at a maxi- 

 mum during the 1917-1949 period (Figure 45). Greatest shore 

 stability occurred between 1852 and 1917. 



78 



