Propagation of ULF/ELF electromagnetic fields along the seafloor interface (assumed to be a plane boundary separating two semi-infinite conducting media) is considered. Earlier expressions for the electromagnetic fields generated by a straight current source of infinite length are applied to the sea/seabed interface. The field components are calculated numerically and are compared to the field components in seawater of infinite extent. At the seafloor boundary, the fields can propagate longer distances because of the lower seabed conductivities. The new horizontal component of the magnetic field generated as a result of the existence of the sea/seabed interface becomes larger than the vertical component of the magnetic field at large distances; it is also more sensitive to the conductivity of the seabed at low frequencies. The results indicate that there is an optimal frequency at which two of the field components have a maximum field intensity at a certain distance from the source. Some practical applications are discussed.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.