| Title | Deep Electrical Structure Beneath the Taupo Volcanic Zone and the Source of Geothermal Heat |
|---|---|
| Authors | H.M. Bibby, G.F. Risk, T.G. Caldwell, Y. Ogawa, S. Takakura & T. Uchida |
| Year | 2000 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | Electrical resistivity surveys now provide images of the electrical structure beneath the Taupo Volcanic Zone (TVZ) to depths that exceed those of the base of the geothermal systems. Multiplesource bipole-dipole surveys show there are three distinctive zones in the upper crust across the TVZ. Highly conductive basins up to 5 km deep, found on both the east and west sides of the TVZ, are separated by a resistive structure beneath the (cold) Taupo Fault Belt. At greater depths, inversion of magnetotelluric data along a profile crossing the TVZ shows a significant conductive structure at a depth of about 10 km. This conductor may be associated with magma within the crust and hence may represent the ultimate source of geothermal heat. |