Levels of 137Cs in muddy sediments of the seabed of the Bay of Cádiz, Spain. Part I. Vertical and spatial distribution of activities

This is the first of a two-part paper. This first part describes a detailed study conducted of the spatial and vertical distribution of the concentration of the radionuclide 137Cs, utilising columns of sediment extracted from the seabed of the Bay of Cádiz (Spain) as specimens. The activity concentrations have been measured by means of gamma spectrometry using a HPGe detector and 137Cs is used as an indicator of the sedimentation and contamination processes in the zone. At the same time the relationship between the levels of activity found and other hydrodynamic and sedimentological variables characteristic of the zone have been studied. The experimental results obtained will also serve to develop a model of the distribution of 137Cs, which will be presented in the second part of this paper.