GEOSCAN, résultats de la recherche


TitreControlled source electromagnetic deep sounding: theory, results and correlation with natural source results
AuteurBoerner, D E
SourceSurveys in Geophysics vol. 13, issue 4-5, 1992 p. 435-488,
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 16891
ÉditeurSpringer Nature
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetslevés électromagnétiques; champs électromagnétiques; études de la croûte; établissement de modèles; conductivité; simulations par ordinateur; interprétations électromagnétiques; géophysique; géomathématique
Illustrationsgraphs; formulae; tables
Résumé(disponible en anglais seulement)
Controlled source electromagnetic (EM) methods represent a unique set of geophysical experiments which can be used to determine the properties and state of the deep continental crust. Unlike natural source EM methods, an artificial EM source technique can be designed to optimize resolution and minimize interactions with local structure. The major drawbacks include restricted depth penetration, insufficient data sets and a limited number of modelling algorithms. Information about the electrical conductivity at lower crustal depths can be obtained but at the expense of requiring large moment sources, sophisticated processing techniques and data redundancy. Moreover, EM data are sufficiently complicated that numerical modelling is often necessary for quantitative interpretation. It is therefore essential to record enough information to justify the choice of interpretation algorithms, particularly since controlled source EM forward modelling routines are generally very restrictive and not widely available. As most interpretations are based on layered earth models, observations of all the EM field components can be useful for testing the "dimensionality" of the data and for justifying interpretations.