Magnetotelluric imaging of upper-crustal convection plumes beneath the Taupo Volcanic Zone, New Zealand

• Published in: Geophysical research letters 2012-01, Vol.39 (2), p.n/a
• Main Authors: Bertrand, E. A., Caldwell, T. G., Hill, G. J., Wallin, E. L., Bennie, S. L., Cozens, N., Onacha, S. A., Ryan, G. A., Walter, C., Zaino, A., Wameyo, P.
• Format: Article
• Language: English
• Subjects: Arrays; Broadband; Convection; Ductile brittle transition; Earth sciences; Earth, ocean, space; Exact sciences and technology; Geophysics; geothermal; Imaging; Inversions; Magnetism; magnetotellurics; Mineralogy; Petrology; Plate tectonics; Seismic phenomena; Taupo Volcanic Zone; Three dimensional models
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL050177

Broadband MT (magnetotelluric) data were recorded that form an array of measurements at the south‐eastern margin of the TVZ (Taupo Volcanic Zone), in the central North Island of New Zealand. These array data are used to investigate mechanisms by which the TVZ's extraordinarily high heat flux is transported to the surface. Taken together with seismological data, these MT data show compelling evidence that support a model of hydrothermal convection within the brittle (upper ∼6–7 km) part of the crust. Both 2‐D and 3‐D inversion models of these MT data show vertical low‐resistivity zones that connect surface geothermal fields to an inferred magmatic heat source that lies below the brittle‐ductile transition. Key Points 2‐D and 3‐D resistivity models are generated from ~200 MT sites in the SE TVZ Low‐resistivity plumes (3‐8km) connect geothermal fields to deep heat source MT models support hydrothermal convection in the brittle crust