APPENDIX A 

 SELECTED SOUND VELOCITY CROSS-SECTIONS 



Figure 1 gives the location of the 12 sound velocity cross-sections shown 

 as Figures A-2 through A-13. The basic contour interval used is 10 m/sec 

 (sliown by solid line), A subsidiary 1495-m/sec contour (dashed line) has been 

 added on all figures for better definition of the deep sound channel. When 

 present, the following sound velocity features are shown on each cross-section: 



• deep sound channel axis (primary minimum) 



• secondary subsurface minima (including the upper sound velocity 

 minimum, minima associated with other perturbations above deep 

 axial depth, and minima associated with perturbations below deep 

 axial depth) 



• subsurface maxima (including sonic layer depth, the intermediate 

 sound velocity maximum, maxima associated with other perturbations 

 above deep axial depth, and maxima associated with perturbations 

 below deep axial depth) 



• critical (limiting) depth. 



The locations of individual sound velocity profiles are shown by ticks inside 

 the bottom margin on each cross-section. These profiles were plotted at NODC 

 standard depths and analyzed at 5- and 10-m/sec intervals to either the bottom 

 or a maximum depth of 5000 meters. 



The bathymetric profiles shown on each cross-section were drawn from a 

 large number of sources, including: 



• Five 1:2,000,000 charts for the southern Somali, southern Arabian, 

 Mid-Indian, and North Wharton Basins and the Bay of Bengal provided 

 by R. L. Fisher, Scripps Institution of Oceanography (personal 

 communication) 



• The chart of Fisher, et al . , 1968 (northern Somali and southern 

 Arabian Basins) 



• The chart of Curray and Moore, 1971 (Mid- Indian Basin and Bay of 

 Bengal) 



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