On July 1, 1967, the Scripps Institution of Oceanography began 

 a contract vrith the Undersea Surveillance Oceanographic Center of 

 NAVOCEANO to prepare a series of charts and a digital tape of 

 bathymetric soundings of the North Pacific Ocean. 



The purposes of these efforts are many, and two are of immedi- 

 ate importance. 



Increased studies of the origin and history of the Pacific 

 basin are important to the fields of Marine Geology and Geophysics. 

 Detailed bathymetric sea floor charts are critically needed in 

 such studies. 



Within many research organizations, studies of sound trains- 

 mission in water along selected paths are often interrupted by 

 topographic features. Here, reliable charts are also important. 

 The majority of existing sea-floor contour charts, however, have 

 been found to be of a smaller scale, contour Interval, or too old 

 to aid in these studies. 



Four series of charts are being produced: physiographic charts 

 (10 sheets); bathymetric contour charts (10 sheets); bathymetric 

 contour charts at approximately 1:1,000,000 scale (I60 sheets); 

 and 3 atlases of bathymetric contour charts. 



Ihe charts are a compilation and interpretation of the best 

 bathymetric contours and sounding data available, and they present 

 a complete series of topographic and physiographic charts for ease 

 in referencing the floor of the North Pacific Ocean. They are 

 designed for use by interested persons or groups working in the 

 marine sciences as a quick reference to bathymetric contours and 

 physiographic provinces. 



Figure 1 shows the distribution of and numbering system for 

 location of the charts. The heavy borders are small-scale re- 

 gional contour and physiographic charts. Areas I, II, and III 

 are boiindarles of the three atlases. Area I is contoured, and 49 

 charts are published in the Bathymetric Atlas of the Northwestern 

 Pacific Ocean. Figure 2 shows a page from that atlas. (H. 0. 

 Pub. 1301.) 



The atlas of area I contains 49 bathymetric charts covering 

 nearly 7-1/2 million square miles of the North Pacific Ocean 

 between 4°S and 60°N latitude and between 100°E and l60°E longi- 

 tude, including the South and East China, Yellow, Japan and 

 Okhotsk Seas. 



346 



