52 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



collected in the past have dealt mainly with the near-surface 

 sound velocity structure of the oceans and the effects of surface 

 backscatter of sound. Newer sonars use all possible modes of 

 sound propagation, and as a consequence have made us aware of 

 the extreme sparsity of subsurface environmental data. To 

 provide, this urgently needed information, the Navy has both 

 stepped up its own effort and has contracted with commercial 

 exploration companies for surveys of all critical areas. Over 5 

 million square miles of ocean have already been surveyed, with 

 vast areas of the Atlantic and Pacific Oceans programmed for 

 early effort. 



In order to obtain a broad sampling of the ocean with a minimum 

 of ship time, these surveys depart from the conventional survey 

 of intersecting grid lines and make a statistical sampling of 

 physiographic provinces of the sea floor. The basic hypothesis 

 in this type of survey is that the ocean is divisible into provinces, 

 so that a limited number of samples within each province will be 

 sufficient to define the characteristics of the province as a whole. 



As previously described, other types of supporting environmental 

 information are required to define adequately and predict acoustic 

 characteristics such as the nature of the ocean bottom and its 

 material, structure, and topography. Sound velocity profiles 

 through the entire water column, either measured directly or 

 calculated from water temperature and salinity, are also collected 

 on all surveys to define propagation paths. Special procedures 

 to measure sound scattering by marine life also are established. 



Oceanographic and acoustical information collected on all sur- 

 veys is stored in data banks after processing and analysis, where 

 it is available to all qualified personnel for further study. 



MARINE LIFE 



Because some marine organisms habitually adhere to submerged 

 objects in the shallow water zones of the oceans, the Navy has 

 undertaken studies designed to investigate their geographic and 

 seasonal abundance. The study of fouling organisms, begun in 

 1956 with a biological survey of the approaches to Chesapeake Bay, 

 has since expanded in scope to include nine localities, six of which 

 are outside the continental limits of the United States. 



