2. Carolina Beach Inlet . 



Because of the erosion at Carolina Beach, Carolina Beach Inlet has a 

 well-defined offset, the southern ocean edge displaced landward of the 

 projected ocean edge of Masonboro Beach. The part of the inlet channel 

 between the barrier islands is arched northward. These features can be 

 seen clearly in the ERTS-1 photos. Comparison with the overlay reveals 

 that the inlet is migrating northward with a concomitant increase in the 

 bending of the channel. There does not appear to be a significant shift 

 in position of the' mouth of the channel. However, close examination of 

 the inlet in the underf light mosaic (19 July 1972) shows a long, (about 

 1,000 feet) narrow bar normal to the shore, detached from land, positioned 

 on the south side of the inlet, and extending seaward from well within 

 the inlet. This bar is faintly visible in Figure 8. Examination of 

 underf light -imagery subsequent to 19 July 1972 shows that the northern 

 tip of the Carolina Beach extension accreted and filled in the gap 

 between it and the linear bar, the latter forming a sort of cap to the 

 barrier island's growth. This accretion was accompanied by erosion on 

 the north side of the channel. The combination of accretion and erosion 

 accounted for the increase in the channel arching. 



3. Masonboro Beach . 



No significant change in the shoreline position of Masonboro Beach 

 was observed in either the ERTS-1 or underflight imagery. Evidently, the 

 sand budget along this coastal segment was relatively stable for the time 

 period under consideration. Most of the sand replenishing the southern 

 part of Masonboro Beach was probably derived from the outer bar of 

 Carolina Beach Inlet during littoral drift toward the north. Some littoral 

 drift at the north end probably moved south from the shoal on the south 

 side of Masonboro Inlet. 



4. Masonboro Inlet. 



A narrowing of the channel through Masonboro Inlet occurred between 

 the two ERTS-1 observations shown in Figures 8 and 9. The narrowing 

 resulted from accretion of the northern tip of Masonboro Beach; the 

 northern edge of the inlet channel remained stationary. An increase in 

 size of the shoal on the south side also narrowed the channel along the 

 above-water part of the jetty. Recent survey data have revealed a steady 

 northward migration of the channel thalweg since the installation of the 

 weir jetty (Fig. 12). Thus, the ERTS-1 photography probably reflects a 

 part of this general trend. 



Accretion of the northern tip of Masonboro Beach and the increase in 

 shoaling along the south side of Masonboro Inlet may be due to any combi- 

 nation of several factors in- addition to normal shoaling associated with 

 inlet tidal flow. One of these factors is northbound littoral drift. 

 During the fall and winter months, waves approach the area around Mason- 

 boro Inlet more frequently from the northeast and east, producing south- 

 bound littoral currents. During the spring a transition period is 



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