(National Oceanic and Atmospheric Administration, 1973). Mean high water 

 (MHW) was assumed to be 2.05 feet above mean sea level (MSL) and mean low 

 water (MLW) was assumed to be -2.05 feet MSL. The beach profile was then 

 divided into five segments: Berm, berm to MHW, MHW to MSL, MSL to MLW, 

 and below MLW (Table 1). (No dunes were sampled in this study.) The 

 berm segment was the flat part of the beach extending seaward to the point 

 where the beach slope becomes at least 1 in 50. The berm to MHW segment 

 extended from the seaward edge of the berm segment to a point 2.05 feet 

 above MSL on the profile. The below MLW segment extended seaward from a 

 point 2.05 feet below MSL. 



The analysis of sample set B differs from the flow chart (Fig. 8) in 

 the following significant ways: 



(a) No check was made with sieves for the sample set B and 

 no adjustment was made to the Rapid Sediment Analyzer (RSA) out- 

 put. 



(b) The RSA equipment used for sample set B was the same as 

 for sample set A, only it had been dismantled and rebuilt in 

 another location, and the transducer had been changed. 



(c) The procedures and the computer program used to produce 

 RSA analyses had been improved (C. Judge, geologist, CERC, per- 

 sonal communication, July 1976) . 



2. Units. 



Two units (millimeters and phi) are used for sand size. The phi unit 

 is defined by: 



4, = -log2D (1) 



where D is the diameter in millimeters (Krumbein, 1939, p. 566). In 

 this report, phi units have several conveniences, particularly in relat- 

 ing mean sizes obtained from sieves and the RSA. However, the engineer 

 unfamiliar with phi units must remember three characteristics of these 

 units (U.S. Army, Corps of Engineers, Coastal Engineering Research Center, 

 1975, p. 4-15): (a) Sand diameter increases as phi size decreases; (b) 

 the phi unit is dimensionless, so differences in sand size in phi units 

 are difficult to interpret physically; and (c) averages of sand size in 

 phi units are the geometrical mean of the sample means, rather than the 

 arithmetic mean. All averages in this paper are averages of sizes in phi 

 units. 



3. RSA Analyses of the Samples . 



The RSA is modeled after the settling tube at Woods Hole Oceanographic 

 Institution, Woods Hole, Massachusetts (Zeigler, Whitney, and Hayes, 1960), 

 It uses the change in the pressure differential between two water-filled 



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