UNCLASSIFIED 



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28 meters (96 feet) per year. Profile lines updrift (east) of the groin field 

 accreted at a rate of 1.10 meters (3.6 feet) per year as measured at the MSL 

 shoreline and showed an increase of 3.68 cubic meters per meter (1.47 cubic 

 yards per foot) per year in sand stored on the beach above MSL. The shoreline 

 within the groin field accreted at a rate of 3.45 meters (11.3 feet) per year 

 and the beach unit volume increased at a rate of 11.92 cubic meters per meter 

 (4.75 cubic yards per foot) per year, including beach fill. Downdrift of the 

 groin field the profiles showed an average MSL shoreline gain of 0.66 meters 

 (2.2 feet) per year and an average unit volume loss of 0.12 cubic meter per 

 meter (0.05 cubic yard per foot) per year. The largest changes measured 

 resulted from the storm of 22 March 1973, which eroded the shoreline an average 

 of 20 meters (65.6 feet) and removed an average of 29 cubic meters per meter 

 (11.6 cubic yards per foot) of beach front above the MSL elevation. Beach 

 changes were found to be seasonal, with the least amount of sand above MSL 

 from January to May. The data taken provide no information on profile changes 

 below MSL, either natural changes or changes caused by the groin field. How- 

 ever, bathymetric survey data collected within the groin field by the U.S. 

 Army Engineer District, New York, and summarized in this report show that 

 underwater changes are larger than changes on the beach and occasionally 

 are opposite in sign. 



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