Radiometry as a technique for use in coastal research

Natural radioactivity in certain heavy minerals makes it possible to locate and follow, in time and space, such components in coastal sands. In this paper, the sensitivity of radiometric techniques is demonstrated in measurements carried out in the laboratory and in the field. In the laboratory, on the beach and on the sea floor, indications were found that transport processes acting on light and heavy minerals often result in net transport modes in opposite directions. A simplified transport model is discussed which describes this selective transport semi-quantitatively. This model calculates trajectories of individual grains, using physical expressions for the forces acting on them. The model incorporates turbulence and vortex motion in an effective viscosity coefficient.