78 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



Bottom Contour (BC) charts are available for approximately 

 94 areas covering large portions of the North Atlantic and North 

 Pacific Oceans. A transition is being made from the BC series 

 of charts to an HO/BC series, which should provide more up-to- 

 date bathymetry and expanded coverage. 



Because of its vast bathymetric data holdings, the Navy is one 

 of the principal contributors to the General Bathymetric Chart 

 of the Oceans, a program of the International Hydrographic 

 Bureau to produce up-to-date charts of the world's oceans. 

 Responsibility for providing data for particular ocean areas was 

 assigned to its 40 members, and the Navy, in addition to satisfying 

 its own responsibilities, has helped many member nations in 

 meeting their commitments. 



MARINE GEOLOGY 



The composition and physical characteristics of sediments and 

 rocks affect the absorption, reflection, and scattering of acoustic 

 energy. Also, a knowledge of the type and distribution of sedi- 



New Oceanographic Atlas, being prodv/^ed serially, gives latest information 

 on the physics, chemistry, biology, and geology of the oceans. 



