Magneto-hydrodynamic seismic source and a method of marine seismic surveying

Abstract

A magneto-hydrodynamic seismic source includes a casing having a central longitudinal axis; a fluid flow channel, and a plurality of electromagnets arranged along the channel for generating a uniform magnetic field at right angles to the central longitudinal axis of the channel, a first electrode positioned on a first side of the fluid flow channel, the first electrode being positioned opposite a second electrode that is positioned on a second opposing side of the fluid flow channel, and a controllable power source in electrical communication with the first electrode and the second electrode for generating a continuously varying electric field between the first electrode and second electrodes to generate a continuously varying inflow of seawater into the first end of the fluid flow channel with a corresponding continuously varying outflow of seawater in the form of a seismic signal being produced from the second end of the fluid flow channel.