108 BKOECKER [CHAP. 4 



past 2000 years. 226 Ra offers great promise of defining the age of surface ocean 

 water with respect to mixing with the deep sea ; and 90 Sr, 137 Cs and bomb 14 C 

 results should resolve the problem of the vertical mixing rates for the upper 

 1000 m of the ocean. Isotope data are most valuable when used as boundary 

 conditions for oceanic circulation models derived from independent oceano- 

 graphic observations. 



References 



Arnold, J. R. and E. C. Anderson, 1957. The distribution of 14 C in nature. Tellus, 9, 28-32. 

 Bien, G. S., N. W. Rakestraw and H. E. Suess, 1960. Radiocarbon concentration in 



Pacific Ocean water. Tellus, 12, 436-443. 

 Bowen, V. T. and T. L. Sugihara, 1960. Strontium-90 in the "Mixed Layer" of the Atlantic 



Ocean. Nature, 186, 71-72. 

 Broecker, W. S., R. Gerard, W. M. Ewing and B. C. Heezen, 1960. Radiocarbon in the 



Atlantic Ocean. J. Geophys. Res., 65, 2903-2931. 

 Broecker, W. S. and E. A. Olson, 1959. Lamont radiocarbon measurements VI. Amer. J. 



Sci., Radiocarbon Suppl., 1, 111-132. 

 Broecker, W. S. and E. A. Olson, 1960. Radiocarbon from nuclear tests II. Science, 132, 



712-721. 

 Broecker, W. S., E. A. Olson and J. Bird, 1959. Radiocarbon measurements on samples 



of known age. Nature, 183, 1582-1584. 

 Burling, R. W. and D. M. Garner, 1959. A section of 14 C activities of sea water between 



9°S and 66°S in the southwest Pacific Ocean. N. Z. J. Geol. Geophys., 2, 799-824. 

 Craig, H., 1957. The natural distribution of radiocarbon and the exchange time of carbon 



dioxide between atmosphere and sea. Tellus, 9, 1-17. 

 Craig, H., 1958. Distribution of radiocarbon and tritium; cosmological and geological 



implications of isotope ratio variations. Nat. Acad. Sci., Nat. Res. Council Pub., 572, 



135-147. 

 DeVries, HI., 1958. Variations in concentration of radiocarbon with time and location on 



earth. Koninkl. Ned. Akad. Wetenschap. Proc, 61B, 1-9. 

 Fergusson, G. J., 1958. Reduction of atmospheric radiocarbon concentration by fossil fuel 



carbon dioxide and the mean life of carbon dioxide in the atmosphere. Proc. Roy. 



Soc. Austral., 243, 561-574. 

 Fonselius, S. and G. Ostlund, 1959. Natural radiocarbon measurements on surface water 



from the North Atlantic and Arctic Sea. Tellus, 11, 77-82. 

 Koczy, F. F., 1958. Natural radium as a tracer in the ocean. Proc. Second U.N. Intern. 



Conf. Peaceful Uses Atomic Energy, 18, 336-343. 

 Lai, D., E. D. Goldberg and M. Koide, 1900. Cosmic-ray-produced silicon-32 in nature. 



Science, 131, 332-337. 

 Munnich, K. O., 1957. Heidelberg natural radiocarbon measurements I. Science, 126, 



194-199. 

 Ostlund, H. G., 1957. Stockholm natural radiocarbon measurements I. Science, 126, 493-497. 

 Rafter, T. A. and G. J. Fergusson, 1958. Atmospheric-radiocarbon as a tracer in geo- 

 physical circulation problems. Proc. Second U.N. Intern. Conf. Peaceful Uses Atomic 



Energy, 18, 526-532. 

 Revelle, R. and H. E. Suess, 1957. Carbon dioxide exchange between the atmosphere and 



the ocean and the question of an increase of atmospheric CO2 during the past decades. 



Tellus, 9, 18-27. 

 Tamm, C. O. and G. G. Ostlund, 1960. Radiocarbon dating of soil humus. Nature, 185, 



706-707. 

 Willis, E. H., H. Tauber and K. O. Munnich, 1960. Variations in the atmospheric radio- 

 carbon concentration over the past 1300 years. Amer. J. Sci., Radiocarbon Suppl., 



2, 1-4. 



