ABSTRACT 



The Coastal Engineering Research Center, in cooperation with the 

 Atomic Energy Commission, initiated a multiagency program to create a 

 workable radioisotopic sand tracing (RIST) program. Tagging procedures, 

 instrumentation, field surveys and data handling techniques were de- 

 veloped which permit collection and analysis of over 12,000 bits of 

 information per hour over a survey track of approximately 18,000 feet. 

 Data obtained can be considered as nearly synoptic observations of sedi- 

 ment transport in a single environmental zone or in adjacent beach, surf 

 and offshore zones . 



Studies at Surf, California, indicate that sand labeled with the 

 radioisotope of gold 198-199 provides much more data for analysis of 

 sediment movement than does sand labeled with xenon- 133. Surveys con- 

 ducted confirm that, in response to any given set of wave conditions, a 

 very different rate of sediment movement occurs in the zones between the 

 high water line and -15 feet mean lower low water. Because of these 

 differences, tracing surveys confined solely to the foreshore or offshore 

 zone produce data only partially indicative of transport in the zone of 

 immediate concern to coastal engineers. While an accurate determination 

 of sediment drift volume remains illusive, qualitative data on sediment 

 movement useful for engineering purposes can be obtained on a scale 

 heretofore unattainable. 



FOREWORD 



Since July 1966, the Coastal Engineering Research Center (CERC) has 

 directed a multiagency program to develop a workable sand-tracing system 

 capable of operating on the beach, in the surf zone, and offshore. The 

 primary effort is toward the use of radioactive tracers to understand the 

 mechanics, pattern and volume of sediment movement. Results to June 1968 

 were summarized in "Radioisotopic Sand Tracer Study, Point Conception, 

 California", May 1969, by D. B. Duane and C. W. Judge. That report is now 

 out of print; copies may be purchased from the Clearinghouse for Federal 

 Scientific and Technical Information, 5285 Port Royal Road, Springfield, 

 Virginia 22151. The catalog number is AD 690/04. 



This report was prepared by D. B. Duane, Chief, Geology Branch and 

 RIST program director, under the general supervision of G. M. Watts, Chief, 

 Engineering Development Division. It is part of Contract AT(49-ll)-2988 

 (as modified) between the Atomic Energy Commission (AEC) and CERC. Work 

 of the AEC is provided through the Oak Ridge National Laboratory (ORNL) . 

 Other participants in the present west coast studies are: U. S. Army 

 Engineer District, Los Angeles, U. S. Army Mobility Equipment Command, 



