POSSIBLE REVERSAL OF DEEP-SEA CIRCULATION 367 



view that the carbon dioxide of the atmosphere is in equihbrium, not 

 only with the free carbon dioxide absorbed in the sea water, but, 

 through dissociation, wdth the second equivalent of carbon dioxide 

 in the oceanic bicarbonates. The sum-total of such free and loosely 

 combined carbon dioxide available at present as a possible supply 

 for the atmosphere may be some twenty-five times the present atmos- 

 pheric content. Schloesing held that any depletion of the atmos- 

 pheric content would be followed by emanation from the ocean, and 

 any excess acquired by the atmosphere would be followed by oceanic 

 absorption, and hence great changes in the atmospheric content 

 would only be brought about by reducing or increasing the large 

 sum-total of atmospheric and oceanic supply. This was a contri- 

 bution of the fir-st order to the problem of atmospheric regulation. 

 It is necessary for a geologist, however, to recognize that the exchange, 

 and even the equilibrium itself, are dependent on geological and 

 physical conditions. At periods in which the oceanic bicarbonates 

 were most abundant, the amount of free and loose carbon dioxide 

 in the ocean may perhaps have reached 30 or 40 times the present 

 atmospheric content, while, on the other hand, it may have fallen 

 to a very low figure when the ocean was depleted of carbonates. 

 It is necessary also to recognize that the diffusion of gases in water, 

 so far as it is covered by experiment, is a slow process, and com- 

 putation seems to show that the supply of carbon dioxide to the 

 atmosphere might be much too slow to offset its consumption under 

 certain geologic conditions, unless effectively aided by oceanic cir- 

 culation. The active superficial circulation immediately assignable 

 to the winds would aid somewhat, but its competency is limited. 

 It was in an attempt to determine the functions of the deep-sea 

 circulation in this interchange that the conceptions of this paper 

 arose. 



In an endeavor to find some measure of the rate of the abysmal 

 circulation, it became clear that the agencies which influenced the 

 deep-sea movements in opposite phases were very nearly balanced. 

 From this sprang the suggestion that, if their relative values were 

 changed to the extent implied by geological evidence, there might 

 be a reversal of the direction of the deep-sea circulation, and that 

 .this might throw light on some of the strange climatic phenomena 



