referenced (Fig. 8) . Negative distances indicate stations landward of 

 the MSL- intercept with the initial profile; positive distances indicate 

 seaward stations. 



For a profile crossing the MSL elevation, the MSL-intercept was 

 linearly interpolated. When a profile did not cross the MSL elevation, 

 but reached the +2-foot MSL elevation, the MSL-intercept was determined 

 by extrapolating the profile along the slope defined by the two seaward- 

 most surveyed points on the profile. 



The cross-sectional area under each profile was computed. This area 

 is bounded by three lines: (a) a vertical line projected from the land- 

 wardmost distance common to all surveys on a given profile line, (b) a 

 horizontal line at the MSL elevation, and (c) the surveyed profile. The 

 calculation was accomplished by summing 1-foot horizontal slices through 

 the area under the profile (Fig. 9) . The area change from the initial 

 survey was then computed by subtracting the initial profile area from 

 each subsequent profile area. Cross-sectional areas were computed in 

 square feet and then converted to unit volume in cubic meters per meter 

 of shoreline (1 cubic meter per meter = 10.8 cubic feet per foot). Areas 

 were not computed under those profiles not reaching the +2-foot elevation 

 at the seaward end. 



A time-history plot in Appendixes C and D identifies dates of profile 

 surveys, documented storm events, groin construction, and beach fill. 



The plots in Appendix E are profile envelopes; i.e., the plots show 

 two lines drawn through the upper and lower extremes of the surveyed 

 sand elevations on each of the profile lines. The envelope of extremes 

 usually contains points from many different surveys, rather than trace 

 a particular eroded or accreted profile found during one survey. 



V. RESULTS 



During the 11-year study, 1,291 profile line surveys were collected. 

 Surveys were scheduled monthly (or more often) for the first 18 months 

 (Fig. 4). This frequency dropped to (approximately) quarterly surveys 

 during 1964 to 1967. From 1968 to the end of the study, the data collec- 

 tion effort was concentrated during the winter months when there was a 

 higher probability of the occurrence of northeasters. Scheduled surveys 

 were generally bimonthly during the calmer weather of late spring to 

 early fall. 



The profile changes analyzed in this report are grouped by short-term 

 and long-term changes. Short-term changes are changes measured between 

 surveys; i.e., changes which occur over an interval of a few hours or days 

 (in the case of storms) or over a few months (in the case of seasonal 

 changes). Long-term changes that can be identified in the profiles in- 

 clude the yearly changes and may suggest longer term trends reflecting 

 a relative rise in sea level and barrier island migration. 



