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Titre3-D magnetic imaging using conjugate gradients
AuteurPilkington, M
SourceGeophysics vol. 62, no. 4, 1997 p. 1132-1142, https://doi.org/10.1190/1.1444214
Année1997
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 38495
ÉditeurSociety of Exploration Geophysicists
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1190/1.1444214
Mediapapier; en ligne; numérique
Formatspdf
ProvinceOntario
SNRC41P/01
Lat/Long OENS-80.1667 -80.0000 47.1167 47.0500
Sujetsétablissement de modèles magnétiques; anomalies magnétiques; susceptibilité magnétique; formations ferrifères; Province de Southern ; géomathématique; géophysique; Précambrien
Illustrationsmodels; graphs
Résumé(disponible en anglais seulement)
A 3-D inversion approach is outlined that determines a distribution of susceptibility that produces a given magnetic
anomaly. The subsurface model consists of a 3-D array of rectangular blocks, each with a constant susceptibility.
The inversion incorporates a model norm that allows smoothing and depth-weighting of the solution. Since the number of parameters can be many thousands, even for small problems, the linear system of equations is inverted using a preconditioned conjugate gradient approach.
This reduces memory requirements and avoids large matrix multiplications. The method is used to determine the 3-D susceptibility distribution responsible for the Temagami magnetic anomaly in southern Ontario, Canada.
GEOSCAN ID205773