dispersion at an inlet. In this study, 2,000 pounds each of 4 colors, of 

 dyed sand were used. The study area was sampled periodically for about 

 1 month with samples obtained along ranges spaced at 100-foot intervals. 

 Results of both of these studies were qualitative only. 



Recently, the Scripps Institute of Oceanography (Komar, 1969) re- 

 ported the results of using fluorescent tracers through three beaches, 

 two of which were in Southern California. In general the area studied 

 extends from the plus 3-foot contour to the minus 3-foot contour , with 

 sand injected as a band of sediment raked into the beach face at low 

 tide. Where the sand had to be placed through the water column, the sand 

 was packaged in paper bags; these were manually broken open after place- 

 ment on the bottom. Between 70 to 200 samples were recovered from an area 

 about 200 by 1,000 feet; 100 to 200 pounds of sand were used. Results 

 were expressed as maps showing number of grains of tracer per kilogram. 

 Volume samples (grab) were obtained rather than surface samples (greased 

 card), usually obtained in fluorescent studies. In the results reported, 

 samples were usually obtained only once for each test. At Silver Strand 

 Beach (south of San Diego) five tests were conducted. The maximum 

 elapsed time from tracer injection to sampling and conclusion of the 

 survey was 4 1/2 hours; usual duration was 1 hour. Results expressed are 

 qualitative and quantitative. However, the quantity of sand moving must 

 be considered a minimum because the maps resulting from the study show 

 marked truncation at the seaward limits of the sample zone with indica- 

 tions that maximum transport occurs seaward of the low-tide line. The 

 RIST study has confirmed that the maximum velocity of transport is in the 

 inshore zone, not on the submerged foreshore. 



Perhaps the most widely known and most often quoted work on fluores- 

 cent tracers is that by James C. Ingle (1966). In his research, Ingle 

 investigated five California beaches; the areal extent studied was about 

 the same in all cases. At Trancas Beach, west of Los Angeles, samples 

 were collected as much as 3 hours after injection of the tracer; this was 

 the longest study. In all studies, packets of tagged sand were placed at 

 specific intervals along a line seaward from the beach backshore. At 

 Trancas, six packets of sand weighing 5 pounds each were placed at 25-foot 

 intervals along the line from mean sea level to a depth contour of 4 feet 

 below mean lower low water. In all, only 57 data points were sampled over 

 a rectangular area 200 by 850 feet; a total area of 170,000 square feet. 

 The 57 data points, each represented by a 9-square inch sample (3- by 3- 

 inch greased card) cover a total area of 3.56 square feet. This sampled 

 area represents 0.000021 of the total area on which to base contours of 

 grain count. 



In the following paragraphs, data on the RIST test at Surf, California 

 in October 1968 are used for a comparison with some of the studies briefly 

 reviewed above. On 4 October 1968, in a period of 44 minutes, an area 

 900 by 1,300 feet (more than 1 million square feet) was surveyed. The 

 survey started 2 hours after injection of the isotope, and extended from" 

 the plus 3- foot contour to about the minus 15-foot contour. In the course 



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