SUMMARY OF MICRORELIEF PHOTOGRAPHIC DATA 



Various parts of the surfaces of 39 intermediate 

 topographic features of the Pacific Ocean, Indian Ocean, 

 Arctic Ocean, and attached water bodies were sampled 

 photographically. These intermediate features were parts 

 of 12 major topographic features or provinces. (The photo- 

 graphic techniques and cameras used are described in the 

 next section. ) Figure 2 is a world map showing the loca- 

 tions of the NEL deep-sea camera stations occupied for 

 this purpose, and their relation to the major underwater 

 topographic features. 



These camera stations were not all preselected to 

 obtain the greatest number of similar or dissimilar sea 

 floor characteristics. Many photographs were taken from 

 oceanographic vessels moving along tracks designated for 

 other scientific programs. Available vessel time along 

 these routes, however, made it possible to obtain photo 

 samplings of a wide variety of sea floor features. 



Table 1 is an overall summary of the photographic 

 data. It relates the 12 major features, the 39 intermediate 

 features, and the associated microrelief as found by random 

 sampling in the areas surveyed. It also gives the heights, 

 lengths, and widths of the visible targets at the sediment- 

 water interface, and the dimensions of free chemical and 

 biological specimens. Although the latter are not permanent 

 parts of the relief, they are included here because of their 

 significance in acoustics. Many crest lengths of physically 

 formed ripples were not determinable from the small-area 

 bottom photographs. 



Table 2, like table 1, relates the major and inter- 

 mediate topographic features and the associated microrelief, 

 but classifies the microrelief into five types based on the 

 five principal agencies responsible for its formation. 



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