Radiochemical dating of nuclear weapon debris precipitated from cyclonic storms over the California coast

Radiochemical analyses of the fission products 140Ba, 89Sr, and 90Sr in precipitation from three Pacific cyclones were examined as functions of time and latitude along the California coast to estimate the fractional contribution of nuclear debris from recent nuclear weapons tests. The estimates are based upon the assumptions that the observed fission products originated solely from announced tests in the atmosphere and were produced with the same relative yields as those reported for U. S. nuclear weapons. The analyses show evidences of fractionation of these fission products in the precipitation along the coast in each of the three cyclone storms studied. In accordance with the given assumptions, the fractionation seems to be associated with the precipitation patterns resulting from the meteorological features of the storms.