Wave Length in Deep Water 



Values for wave length (expressed as a deep-water value) ranged 

 from U9.2O to 989. 2U feet. 



Average Mean Nominal Grain Diameter 



Over Bottom in Shoaling-wave Zone 



Mean-size values were averaged for four samples taken 25 feet apart 

 in the shoaling-wave zone (fig. 3) where MLW depths ranged between 10.1 

 and l4.1 feet. The sampling device, a pipe dredge, permitted taking an 

 integrated sample over a 15-foot distance parallel to shore, and so the 

 average value for the four samples is presumed to represent the average 

 mean size of a 15 x 100 foot area of the bottom. Individual {'M.^) ^ values 

 were determined using a Woods Hole Rapid Sand Analyzer (Zeigler, and others, 

 I96O; Zeigler and Gill, 1959), and the procedure outlined in Harrison and 

 Morales-Alamo (196^1) . The statistics used to estimate the mean nominal- 

 diameters were 



^ ^20 ^ P50 -^ ^80 ,^ , , . 



M„ = (^for summer dataj 



_ 



Pio + P30 ^ P50 -^ P70 "^ P90 ,, . , , , , 



M = (for winter data J 



0.843 



Average (M ) values used in the analyses ranged form 0.23^ to 



mm. 



Range of Tide Over One Tidal Cycle 



The measured tidal range at 15th Street as taJsen from records furnish-^ 

 ed by the U. S. Coast and Geodetic Survey. Values used ranged between 

 2.k and U.7 feet. This was the only independent variable whose values were 

 held constant over several lag periods, a practice which is to be discour- 

 aged. 



Sf 



Mean Slope Over Lower Foreshore of Beach 



The mean slope was determined for a 200-foot distance of the lower 

 foreshore (fig. 3) from measurements at nine stations that were made daily 



60 



