Abstract
The radiocarbon age of deep ocean water, the lapse time after its leaving from the surface, was estimated by resolving two difficulties in the calculation. One is the effect of particulate carbon being added to the deep water, of which correction method is presented. The other is the effect of mixing of water. Considering the process of the deep water formation, we can regard that the age of deep water is an arithmetical mean of those water masses forming the water. The results show various facts. The correction for the particulate carbon fluxes is not important. In the Atlantic the ages of the Antarctic intermediate water and of the Antarctic bottom water decrease with their northward flow. This means the deep currents are interchanging water molecules by mixing. In the North Pacific there is no major source of deep water and a long time, at least 500 years, is necessary for the transport of the bottom water to the surface. The oldest water of about 2100 years old exists in the mid-latitudes of the North Pacific off United States. There is a striking chronocline in the deep water of the South Pacific over the Tonga-Kermadic Trench.
