Geomagnetic Induction in Submarine Telecommunications Cables
27 July 1989
The influences of induced currents on long submarine communications cables have been observed for more than a century. The induced currents originate from Earth and ocean tides, other ocean flows, and variations in the geomagnetic field of external origin. These latter variations originate from changes in ionospheric electrical currents produced by solar and magnetosphere processes. Besides their intrinsic interest, the induced currents, representing integrals of the variations over large geographical regions, can be used for scientific investigations of the ionospheric electrical currents and the Earth's conductivity structure. Present understanding of the induction phenomena is reviewed, as are some recent research results.