is presented yielding an equation for net onshore/ 

 offshore velocity of a given spherical sediment 

 particle. The equation is verified by laboratory 

 measurements and extended. 



NO. 105 - March 1958 



I&II-C "Movement of Bottom Sediment in Coastal Waters by Currents 

 D and Waves; Measurements with The Aid of Radioactive Tracers 

 F In the Netherlands" by J. J. Arlman, P. Santema. and J. N. 

 Svasek 



Sediment movement by currents and waves and ordinary 

 methods of measurement are discussed. Procedures for 

 marking and following movement of bottom sediments by 

 radioactive tracers are also discussed, and charac- 

 teristics of a number of suitable radioactive isotopes 

 are tabulated. Pilot experiments to investigate 

 tracing of sediment movement by use of radioactive 

 tracers are described and it is concluded such a method 

 can be safely employed by ordinary field survey parties. 

 However, manufacture and placement of the radioactive 

 material must be supervised by experts, after which brief 

 safety control is sufficient. 



113 



