UNSATURATED ZONE TRITIUM AND CL-36 PROFILES FROM SOUTHERN AUSTRALIA -THEIR USE AS TRACERS OF SOIL-WATER MOVEMENT

In this paper we present seven unsaturated zone profiles of Cl-36 and three H-3 profiles from southern Australia. All profiles show single p eaks corresponding to high radionuclide fallout from nuclear testing i n the 1950s and 1960s. The profiles are used to estimate rates of wate r movement leading to recharge of the groundwater. Among these profile s is the first profile on which high concentrations of Cl-36 have been found below a 2-m depth. In this profile, H-3 and Cl-36 peaks coincid e. In six of the seven profiles, total Cl-36 fallout was found to be b etween 1.2 and 2.4 x 10(12) atoms m-2, and is of similar magnitude to that found at similar latitudes in the northern hemisphere. Comparison s of soil water fluxes estimated with H-2, Cl-36, and chloride are bri efly discussed.