Dispersal of tritium in Southern Ocean waters

Depth-distribution of tritium in Southern Ocean waters is reported. Decrease of tritium in surface waters from c 2 TU at 38° S. to 40°S. latitude, to 1.3TU and 1.1 TU at 45°S., 55°S., 60°S. and 64°S. latitudes, are very likely to be associated with the presence of convergence and divergence areas at subtropical and subantarctic latitudes in the Southern Ocean. A tritium-free layer has been found to exist at intermediate depths. Significant increase of tritium in waters at and below 4 km. strongly suggests a younger age, a minimum of the order of 25 years for the bottom waters circulating in the entire region to the south of South Australia.