SAND INVENTORY PROGRAM 



by 



Norman E. Taney 

 Coastal Engineering Research Center 



A number of requests over the past five years has caused the U. S. 

 Army Coastal Engineering Research Center (CERC) to initiate its Sand 

 Inventory Program. One such request origj^nated from the District Engineer, 

 U. S. Army Engineer District, Jacksonville, Florida in 1960, who sought in- 

 formation on sources of sand for beach nourishment or beach reconstruction. 

 In another area, New Jersey, the same problem had arisen and was brought 

 into dramatic focus by the great March storm of 1962. In both instances 

 noted and others, it became apparent that in many places conventional 

 sources of sand were becoming or already had been exhausted and that new 

 economical sources of material for beach reconstruction and/or maintenance 

 were necessary. It was logical to look to the nearshore bottom and sub- 

 bottom for new sources. 



In 1961 a literature survey revealed that very little information ex- 

 isted concerning the nearshore bottom and subbottom. Historic U.S.C.& G.S. 

 coast charts were available which, upon comparison, revealed areas of 

 accumulation and erosion. With knowledge of the shore processes function- 

 ing for a given reach of shore, it became possible to predict where probable 

 areas of accumulation would be found. On this basis studies were made along 

 the Atlantic coast of the United States. Then, for a variety of reasons, 

 field exploration was begun at four selected areas off the Atlantic coast 

 of New Jersey in June 1964. 



The landward and seaward, limits of field exploration were approximately 

 15 and 100 feet below mean low water, respectively. The seaward limit was 

 controlled by the fact that present hopper dredge depth capacity is about 

 60 feet below water surface; however, with minor modification a depth of 

 75 feet could be achieved. The additional 25 feet of depth were planned for 

 a new generation of hopper dredges which might be developed as needs became 

 more critical. 



Methods of exploration and positioning were considered early in 1962. 

 Means of positioning were available in which the familiar principle of 

 triangulation is utilized. Two slave radar-transponder beacons are placed 

 on shore in known positions and the distance between them is determined very 

 accurately. The master unit on the survey vessel queries each of the slaves 

 (in turn) and the time of response may be reduced to the distance the master 

 is from each slave. Two electro-mechanical arms then plot the position of 

 the vessel on a mylar base map. 



The first exploration tool is a geophysical instrument called a 

 "Sparker." Its name is derived from the fact that the energy source looks 



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