Vertical distribution of 137Cs activity concentration in marine sediments at Amvrakikos Gulf, western of Greece

• Two sediment cores were studied using 137Cs as a tracer.
• Two peaks are observed due to nuclear tests and Chernobyl accident.
• Diffusivities, as well as 137Cs apparent sedimentation speeds are estimated.

The aim of the present work is the study of 137Cs migration in sediment column taking into account the sedimentation rate in the Amvrakikos Gulf, at the western part of Greece. Marine core sediments were collected and the measurements were performed using the high resolution gamma-ray spectrometry method. The vertical distribution of 137Cs activity concentration, as part of anthropogenic marine radioactivity, provided averaged sedimentation rate by identifying the depths of activity concentrations due to the Chernobyl accident and the nuclear tests signals. Furthermore, 137Cs measurements were reproduced using the proposed one-dimensional diffusion–advection model which provides mainly as an output, the sedimentation rate and the average diffusivity of 137Cs in the sediment column. The proposed model estimates the temporal variation of 137Cs activity concentration from 1987 (one year after the Chernobyl accident) till today (2014).