19. 



That brings up the question of dilution. A popular idea is that 

 dilution is easy to obtain if you have large masses of water. How- 

 ever, the larger the masses of water, the more unpredictable the 

 mechanism of dilution becomes. According to some evidence, saline 

 wastes dumped in the ocean will move as thin horizontal layers thou- 

 sands of times as rapidly as on the vertical plane, so that concentra- 

 tion of high order will be maintained over this horizontal band. There 

 is a great hazard of isotopic movement and concentration along these 

 bands. Those who are familiar with the dilution of industrial waste 

 in larger rivers and harbors know the tendency of these wastes to 

 move in narrow and uncontrolled streams, particularly along the 

 edges. It takes a special circumstance to make available for dilution 

 the full volume of a large mass of water. There are large gaps in 

 our knowledge of the mixing mechanisms in oceanic masses. 



The question of sequestering waste in the ocean came up. 

 Where it is important to note the value of detailed knowledge of the 

 ocean floor and of the water column. We have in the last ten years 

 acquired a very extensive history of the vertical stratification of 

 water, but there are very few areas where the stations have been suf- 

 ficiently close together, and the measurements made with sufficient 

 precision to accurately bound the water mass and determine the rate 

 of water exchange. The measurements are close together in the study 

 of the Carribean deeps, and include recent, very precise measure- 

 ments. These deeps have some ideal characteristics. The deep is 

 bounded by a natural escarpment, and has a single entrance and exit. 

 It allows the oceanographer to assay the rate at which water enters 

 and leaves the area. There is possibility of confinement, and it 

 should be possible to predict the rate of eventual exchange within this 

 confined mass. 



A special hazard had to be considered: when the heat content 

 of possible waste loads was examined, the thermal stability of this 

 area was found to be -- as far as we know -- very close to the limit 

 required for containment. It will require a more careful analysis of 

 the situation to be certain whether we can introduce the heat at the 

 bottom of the stratified water or not. 



A very important point was brought up in the discussion of the 

 tendency of planktonic organisms and their predators to concentrate 

 the more active and troublesome fractions of waste. For example, 

 the long-life elements are taken up quite appreciably by filter -fee ding 

 plankton. We simply don't know what the rate of concentration beyond 



