water level in the tank. A thumb held over the hose discharge 

 while directing it .into a fluted (cupped) filter paper was 

 removed just long enough for the sand and water to be flushed 

 out and into the paper. 



(b) In tank 2, sample pumping proceeded with a large rubber 

 ball in an upper position as shown in Figure 7. After sediment 

 settling, the ball was lowered into stopper position, thus iso- 

 lating water- sediment volume in the glass jar below the ball 

 stopper from the main settling tank volume. The thread-connected 

 glass jar was then carefully removed and its contents poured and 

 flushed into a fluted filter paper. 



(c) In tank 3 (a stainless steel tank), the water sediment 

 mixture was pumped into the tank, then allowed 5 minutes to 

 settle into the extraction mechanism (a small cylindrical sec- 

 tion at the bottom of the tank) (Fig. 7); entry into this 

 section was controlled from above by a large rubber ball stop- 

 per. On completion of particle settling, the ball stopper was 

 lowered into stopper position, thus separating the lower volume 

 of water-sand mixture (1 quart or less) from the large volume 

 of water (40 gallons) above. Next, the ball stopper at the 

 bottom of the extraction mechanism was raised, allowing the 

 contents to be flushed into a fluted filter paper. 



c. Sample Packing, Drying, and Weighing . When the excess water had 

 drained in each method described above, the sediment sample in the fluted 

 filter paper was placed in a plastic bag, identified by collection date 

 and data sheet number, and returned to CERC for laboratory analysis. The 

 samples were air-dried at room temperature with drying completed in a 

 temperature-controlled oven. Dry samples were promptly weighed, in an 

 attempt to assure a uniform moisture content at the time of weighing. 



d. Settling Tube Analysis . A settling tube analysis (visual accumu- 

 lation method) was made of usable samples weighing 2 grams or more. Seven- 

 teen of the 415 samples collected at Ventnor weighed less than 2 grams. 

 The results were reduced to graphs of sediment-size distribution in both 

 sets of data and excerpts from these are included in Appendix D. 



5 . Data Collected . 



The concentration of suspended sediment caused by wave action in and 

 near the surf zone depends on the wave and sediment characteristics, 

 and position with respect to the bottom and the breaker line. The prin- 

 cipal independent variables in this study (eq. 1) are the wave character- 

 istics, the position of the sample, and some information on sediment size. 

 The field data collected for each sample are indicated on a data sheet 

 (Fig. 8). Data recorded on these sheets have been reduced and are tabu- 

 lated in Appendix A for both the Ventnor and the Nags Head data collections, 

 Other necessary data are in Appendixes B, C, and D which are compilations 

 of bottom profiles, tide curves, and particle-size curves, respectively. 



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