retreat which exists for the entire study reach. 



113. It is interesting to note that the sand entrapment rate has re- 

 mained relatively constant since 1849 (Figure 40) . The only perturbation 

 occurred during the 1949-1963 period when the March storm of 1962 greatly 

 changed the inlet (Figures 38, 39, and 40). Poststorm recovery, however, re- 

 turned the system to its prestorm condition; Oregon Inlet is apparently still 

 trapping sand (1980) at about the rate it trapped it in the first 66 years 

 after it opened. As long as Oregon Inlet remains open and unstructured and 

 continues to migrate south, the sand entrapment rate should remain near its 

 1852-1980 average value of 3 x 10 cu m/year. Adjacent ocean shoreline be- 

 havior should remain similar to that shown in Figure 28. As the inlet mi- 

 grates south, the inlet-influenced ocean shoreline 8 km north and south of 

 the throat also will migrate south. 



114. Small, structured Rudee Inlet is presently not acting as a sand 

 trap; littoral sand that is moved into the inlet throat is returned to Vir- 

 ginia Beach by hydraulic means. In the future this inlet will not likely 

 affect adjacent beaches as long as present (1980) conditions prevail. 



115. Past inlets. Inlets have been located, in historic times, in two 

 regions: in northern Currituck Sound and centered around Oregon Inlet (Fig- 

 ure 9). Probably the largest prehistoric inlet (pre-1585), as evidenced 

 primarily by beach ridges, was located at Kitty Hawk, North Carolina (Fig- 

 ure 11). Small ephemeral inlets have been opened during storms, but natural 

 movements of sand along the coast have caused them to close within a few years. 

 Only relatively stable passages through the barrier spits and islands are in- 

 cluded in Figure 9. 



116. Sands are deposited in flood-tidal shoals within the sound, on 

 adjacent sound shorelines, and in ebb-tidal shoals in the ocean after an inlet 

 opens. The net sand loss from adjacent beaches is reflected in an increase 



in the rate of ocean shoreline recession. Conversely, the sound at the inlet 

 gains sand. If the inlet subsequently closes, the flood-tidal shoals fre- 

 quently form a new shoreline or islands in the sound (Figure 37). Inlet 

 closure is usually accompanied by ocean shoreline readjustment such that is- 

 land width at the site of the former inlet increases; i.e., the ocean shore- 

 line builds seaward. 



117. An anomalously wide portion of a barrier island is often a clue to 

 the previous existence of an inlet. In Figure 11, which plots island width 



101 



