A magnetotelluric study of the Alpine Fault, New Zealand |
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| Authors: | Malcolm Ingham & Colin Brown |
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| Institution: | Institute of Geophysics, Victoria University of Wellington, PO Box 600, Wellington, New Zealand. E-mail: ,; Applied Geophysics Unit, University College Galway, Galway, Ireland |
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| Abstract: | Magnetotelluric soundings have been made at seven locations on a 4 km profile crossing the Alpine Fault in the South Island of New Zealand. The 'distortion' techniques of Groom & Bailey (1989 ) and Lilley (1998a , b ) have been used to derive regional apparent resistivity and phase curves that correspond to electromagnetic induction in orientations parallel and perpendicular to the fault. 2-D inversion of the regional responses reveals that a narrow (<1 km wide) conductive zone is associated with the Alpine Fault. This conductor is most probably related to the heating of deep circulating meteoric water in a region in which enhanced temperatures occur at shallow depth due to the tectonic uplift of the Southern Alps. |
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| Keywords: | Alpine Fault magnetotelluric sounding resistivity |
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