Helium flux from a sedimentary basin

The tritium–3He ages of groundwaters collected from the Saijo Basin in Japan were measured. The ages vary between 11.7 and 16.3 years. The 4He flux of >3×104 atoms/cm2 s is calculated by the 4He concentrations and ages. In addition the helium flux of 8.3×105 atoms/cm2 s is calculated at the Higashi-Niigata gas field in Japan. The above two estimates are consistent with the continental helium flux reported in the literature, suggesting that helium flux on the Earthʹs crust is uniform.