Electromagnetic surface fields due to a magnetic dipole buried in a three-layered earth.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8702, 1982 Oct; :1-22
The Bureau of Mines electromagnetic trapped miner location and communications system requires a thorough understanding of through- the-earth electromagnetic wave propagation. An earth model incorporating a magnetic dipole buried in a three-layered earth has been developed. The dipole source is located in the second subsurface layer. By application of proper limiting values, the three-layered model is reduced to two different two-layered models and eventually to the homogeneous half-space model. The solutions are in the form of infinite integrals. A numerical analysis was carried out and a computer program written to evaluate the surface magnetic fields. Numerical values for the magnetic field at the point above the source are presented in a variety of models.
Mine-gases; Mining-industry; Methanes; Methane-drainage; Methane-control; Explosive-gases; Explosive-atmospheres; Underground-mining; Coal-mining; Control-technology; Engineering-controls
IH; Report of Investigations
NTIS Accession No.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8702