Distribution and content of Cs-137/134 and Sr-90 in the water of the North Sea during the years 1982 to 1984

The fundamental distribution pattern of the Cs-137/134 in the North Sea, within certain limits was practically analogous with that of the previous years. In the South and westwards of Jutland, on the basis of steep activity concentration gradients, one can again clearly recognize the boundary between the water coming out of the Channel from the South and the water coming from the North along the English coast. In the surface water, this boundary between the two water masses - as in previous years - lies between 60 E and 70 E. However, in deep water westwards of Jutland, clear differences of the distribution are observed between the years 1982 and 1984. In August/September 1982, a clear front in the entire water column between surface and bottom is present. A comparable pattern, in principle, is indicated by the salinity distribution. In comparison with it, in May/June 1984, a clearly stronger advance of the deep water (on the basis of the activity concentration differences) in the direction of Jutland compared with the surface water is recognizable. Here also this effect appeared in outline to a certain extent in the salinity distribution. Altogether, the content of radio caesium in the water of the North Sea from 1982 to 1984 has decreased by 30%. In 1984, it totalled, approximately 2400 TBq Cs-137/134, only 0.5% of the circa 481000 TBq K-40 present in nature in the North Sea. (orig./HP)