Ch. 15] 



SHORE-CONTROL PROBLEMS 



281 



Shore-line modifications vary widely in scale. The larger changes 

 are those involving considerable physiographic modification, for ex- 

 ample, the truncation of headlands and the associated formation and 

 growth of spits and bars; or the very important formation of barrier 

 beaches and lagoons responsible for the present coastal features of New 



Fig. 5. Fire Island Inlet, New York, after jetty construction, 1941. 

 by Beach Erosion Board.) 



(Photo 



Jersey and the south shore of Long Island. It is in the study of these 

 large-scale changes that geologists have made their greatest contribu- 

 tions to knowledge of shore processes in the past. The information de- 

 veloped is of great value as background for the solution of practical 

 problems of control, but because of the long-term nature of the phe- 

 nomena it is of lesser value in study of the relatively short-term prob- 

 lems of control. Shore-control engineers seek and need immediate con- 

 trol methods, effective for perhaps 20 to 50 years, and, justly, have 

 little direct interest in or use for information about processes involving 

 perhaps thousands of years for their consummation. It is in the study 



