Comments, with reply on 'Magnetotelluric exploration for hydrocarbons' by A.S. Orange

An oversimplification of the treatment of the incidence angle and of the source dependence of magnetotelluric surface impedance in a previous treatment of magnetotelluric exploration of hydrocarbons (see ibid., vol.77, no.2, p.287-317, 1989) is pointed out. The author of the original paper agrees with the comments and recognizes the paper's lack of rigor. He points out that the intent of the paper was to present a broad overview to a general audience and to focus on the utility and applications of the method.<
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