It is found that there are initial and general move- 

 ments of sediment; and initiation, various stages of 

 development, and complete disappearance, of bed 

 ripples. The initial and general motion of small 

 sizes of sediment occur in the laminar boundary layer 

 and axe caused by laminar shear, while similar motions 

 of large sizes of sediment are caused by lift forces 

 in a turbulent boundary layer. Ripples in general 

 are not formed unless the flow is turbulent in the 

 boundary layer. All motion in turbulent flow and the 

 various stages of ripple development are dound to be 

 functions of a dimensionless function representing 

 intensity of flew near the bottom. The phenomena of 

 initiation of turbulence and motion of sediment in 

 the boundary layer at the bottom are expressed in 

 terms of characteristics of the surface waves. 



NO. 76 - June 1955 



II-B "Movement of Sand Around Southern California Promontories" 

 C by Parker D. Trask 



A series of 19 profiles and 175 bottom samples off three 

 rocky promontories - Points Arguello, Conception and 

 Dume - show clearly that sand moves around these promon- 

 tories. The sand moves in three distinct ways: along 

 the beach and surf zone, in the water from sea level to 

 a depth of 30 feet, and between depths of 30 and 60 

 feet. Beyond a depth of 60 feet relatively little sand 

 moves. Underwater diving operations at Point Dume 

 indicate that 60 feet marks the outer limit of ripple 

 formation and distrubance of the bottom by waves. 



NO. 77 - February 1956 



II-B "Behavior of Beach Fill at Ocean City, New Jersey" by 

 C George M. Watts 



£ 



Field survey data taken in connection with a beach fill 

 operation ccanpleted in 1952 at Oceaui City, N. J. are 

 presented and analyzed to evaluate the movement and 

 effectiveness of the fill. The rate of loss of the 

 fill substjintially exceeded the estimated rate, and 

 conclusions are drawn regarding the reasons for this. 

 Conclusions are also drawn relative to future work. 



103 



