摘要：

Concentrations of 7Be, 95ZrNb, 106Ru, and 144Ce were determined in surface water and vertical profiles in the North Pacific Ocean. Latitudinal distribution of radionuclides in equatorial waters differed from previous patterns of both terrestrial and oceanic fallout of long-lived fission products. Fallout rates were quite uniform across narrow latitude belts, with constant amounts of radionuclides occurring both vertically and horizontally in the water mass. The short-lived radionuclides were uniformly distributed in the mixed layer, but decreased in concentration as the thermocline was penetrated. Vertical eddy diffusion coefficients, calculated from 7Be and 95ZrNb data, were 0.50.7 cm2/sec within the upper boundary of the main oceanic thermocline.

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