抄録
The ocean is divided into three layers, i. e., surface (0-100 in), middle (100-1,100 m) and deep (1,100-4,000 m). The concentration of inorganic carbon and the specific activity of radio-carbon relative to that in the air are assumed to be as follows.
Surface Middle Deep Concentration; 24 mg C/l 27 mg C/l 29.4 mg C/l Specific activity; 0.950.90 or 0.89 0.85
Taking into consideration the biological effect, the exc h ange of radio-carbon between air and sea, and isotopic fractionation of radiocarbon among different phases, the calculation was done with respect to the residence time of water in each layer and so forth. The results of calculation show that the specific activity of radio-carbon is determined by various transfer processes in the ocean, which gives the apparent age to deep water as high as 1,300 years, while the mean residence time of water in the layer below the surface is from about 200 to 350 years.
