Land area was gained from 1949 to 1974 on the north shore of Townsend Inlet 

 at a rate of 0.001 square mile per year and lost from the south shore at the 

 same rate, averaging ±400 cubic yards per year. 



Storms appeared to be responsible for the changes which occurred at the 

 north and south ends of Ludlam Beach (Fig. 32). At the south shore of Corson 

 Inlet the average storm loss for seven storms was 20.4 cubic yards per foot 

 per storm, or eight times as great as the average island loss. Conversely, at 

 the south end of the beach storm losses were negligible (<0.3 cubic yard per 

 foot per storm) and lower than any other location on the island. Beaches on 

 the north side of Corson Inlet throat, because of their orientation, were shad- 

 owed by Peck Beach. Longshore transport during a "northeaster" is from north to 

 south so the north beaches, when eroded, receive no sand from updrift sources. 

 The southern beaches, on the other hand, are at the distal and shadowed end of 

 the longshore transport system associated with the storm. 



Not all storms follow the sequence of northern cut and southern fill. A 

 result of the March 1962 storm A^as 0.05 square mile of new land created at the 

 north end of Ludlam Beach (Fig. 62). At an average elevation of 3.6 feet (Fig. 

 70), this was an accretion of 186,000 cubic yards. During the same storm period 

 land was created north of Corson Inlet at the same average rate (0.006 square 

 mile per year) which existed over the 25-year (1949-74) study period. The 

 new land formed south of the inlet was quickly lost. By spring 1963, the south 

 shore was nearly back to its 25-year trend, and by 1965 the south shore losses 

 were greater than the trend. One implication of these findings is that the 

 sand wave shown on Figures 40 and 41, which began moving south in 1962, was 

 composed of the storm-produced material. A further implication is that the 

 sand wave resulted from a unique event which produced a large volume of sand 

 at the north end .of the island. Its initiation, therefore, cannot be predicted. 



Seasonal sand volume changes were very large near Corson Inlet (Fig. 36, 

 profile lines 1 to 4) . The yearly minimum occurred in May, like the island 

 average (Figs. 33 and 35), but the volume maximum above MSL generally occurred 

 earlier in the summer (July to September). Losses correspond to storm periods, 

 while gains are related to nonstorm periods. As shown in Figure 67, when the 

 seasonal range of sand" volume is greater than 12 cubic yards per foot, a net 

 loss of 0.2 cubic yard per foot in excess of a seasonal 12 cubic yards per foot 

 may be expected. Seasonal changes must be decreased to limit the net losses 

 from the north end of the island. 



The farthest distance away from an inlet at which beach behavior is affected 

 by an inlet may be inferred from the survey data. Beaches near the inlets are 

 oriented differently from those along the rest of the island (Fig. 21), a result 

 of the inlet beaches being situated on coastal protrusions. Sand volume changes 

 caused by storms (Fig. 32), seasonal sand volume changes (Fig. 35), and net 

 yearly sand volume changes (Fig. 39) were significantly different on profile 

 lines 1, 2, 19, and 20 when compared to other locations on Ludlam Beach. Corson 

 Inlet appeared to have an effect on adjacent beaches for a distance 2,000 feet 

 south along the northern shore of the island. This corresponded to the part of 

 the coast affected by longshore transport reversals (Fig. 51). Submarine bars 

 also appeared to intersect the coast at the southern end of the inlet-affected 

 beaches. At Townsend Inlet the beach appeared affected 4,000 feet north of the 

 southern shore of the island. 



89 



