646 



Figure 10. Example of Seafloor Sediment Type and Thickness Data 



The seafloor was characterized 

 by the Navy on a global basis, 

 primarily for itse in acoustic 

 Isonar) models. 



This figure shows an esample 

 of the sediment types and 

 sediment thickness (expressed 

 as seconds of two-way travel 

 time) for much of the Atlantic 

 Ocean. 



The mid-Atlantic ridge is seen 

 in both illustrations, but most 

 plainly in the region of very 

 thin sediments ISO.05 sec). 

 Also to be noted is the small 

 region of very thick sediments 

 of the Mississippi Fan, a portion 

 of which was seen through the 

 "lens" of gravity data in 

 Figure 6. 



with its first, albeit somewhat limited, global database of 

 sediment characteristics. 



Applications of interest include the construction of much more 

 accurate geological maps of the seafloor, providing an 

 environmental baseline and guide to the distribution of natural 

 resources. The descriptions of the physical composition and 

 grain size distribution of the sediments contained in the Navy 

 data could help to significantly improve our understanding of 

 the occurrence of sub-bottom features such as salt domes. 

 Distribution of sediments will also allow research scientists to 



study in greater detail seafloor processes such as deposition and 

 erosion of sediments by ocean currents. 



We anticipate that the quality of the data across this database to 

 be quite variable, but the availability of this global compilation 

 would provide a starting point and background for further 

 refinement. Data from the Ocean Drilling Program and other 

 coring programs were incorporated in the initial configuration. 

 As similar data become available these data can be added and 

 the database improved and expanded beyond its use as an 

 acoustic model subcomponent. 



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