Magnetic Anomalies from Conductivity Perturbations in a Conducting Fluid in an External Electromagnetic Field

Magnetic-field perturbations associated with temporalconductivity anomalies in a conducting fluid in an external electromagneticfield have been measured. The measurements utilized a two-layerfluid, the bottom layer of which was conducting saltwater and the toplayer of which was fresh water. A conductivity anomaly was created bycausing a Mode 2 solitary wave to propagate along the saltwater-freshwater interface, and temporal changes in the magnetic field of a fixedelectromagnetic source were measured. The data were compared withtheory, developed here, and were found to be both qualitatively andquantitatively in agreement. The average deviation between thetheoretical calculations and the experimental data was less than 6 percent.