Яндекс.Метрика

V. Mogilatov,M.Goldman,M.Persova,Y.Soloveichik

Том: Journal of Applied Geophysics
Том: 105 , Год издания: 2014
Многотомное издание: Journal of Applied Geophysics
Страницы: 133-137

Аннотация

The influence of displacement currents in conventional geoelectromagnetic (GEM) methods using unimodal transversal electric (TE) or multimodal TE and TM (transversal magnetic) fields is only significant at very high frequencies in the frequency domain or at extremely early times in the time domain. The transient process in the latter includes three stages: the propagation through air, the propagation through earth and the diffusion within the earth. The influence of displacement currents is significant mainly during the former two stages, normally up to several tens to a few hundreds of nanoseconds. The behavior is essentially different in novel GEM methods using a vertical electric dipole (VED) or circular electric dipole (CED) sources of unimodal TM-fields. Under certain geoelectric conditions, the influence of displacement currents in these methods might be crucial at late times as well. This happens, if the model consists of insulating layers. In the absence of displacement currents, such layers would totally mask underlying structures. However, TM-fields including displacement currents depend on geoelectric parameters below insulating layers at late times
индекс в базе ИАЦ: 041504