Okak Bay AMT data-set case study: Lessons in dimensionality and scale

Abstract:

Electromagnetic (EM) exploration for base metals using the natural-source audio-magnetotelluric (AMT) technique has increased significantly during the last five years due to enhancements in all aspects of AMT and to the demand for imaging deeper than conventional controlled-source EM methods. However, regional currents induced by natural sources can be problematic in certain situations, and the appropriate interpretational dimensionality must be known. Herein we demonstrate that a two-dimensional (2D) interpretation is valid for a defined frequency band, but that the effects of large-scale three-dimensional (3D) structures must be considered at lower frequencies. Using an AMT dataset from an area located north of Voisey's Bay, Labrador, Canada, we analyse the responses to determine the appropriate dimensionality and to test them for internal consistency. Maps of the distortion-corrected data …

Año de publicación:

2003

Keywords:

Fuente:

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