An Analogue Model Study of Ocean-Wave Induced Magnetic Field Variations Near a Coastline

Abstract

A laboratory analogue model, described previously by MILES et al. (1977), was used to study the effect of a sloping ocean floor with a shelf, and a step with a shelf, on the magnetic variations induced by ocean waves moving in a static magnetic field. The model measurements indicate that for a shallow ocean, the amplitudes of the magnetic variations are attenuated as the wave travels over the wedge, reach a minimum at the shelf edge, then again increase over the shelf. For the case of the step with a shelf maximum attenuation occurs at the shelf edge followed by an enhancement over the shelf. For both cases, the depth of the fluid over the shelf is the important factor in determining the behaviour of the induced field.