Campaña gravimétrica en el extremo meridional de la zona volcánica de Taupo. (Nueva Zelanda)

Abstract

The gravity survey which we report here forms one part of a multidisciplinary study whose goals are understanding the kinematics, structure, and geodynamic controls, o f the abrupt termination of the Taupo Volcanic Zone (TVZ) in central North Island, New Zealand. The TVZ is the volcanic arc and backarc basin associated with the Hikurangi Subduction Margin (the southern extension o f the Tonga-Kermadec subduction system) along eastern North Island and northeast South Island, New Zealand. The TVZ is characterised by active normal faults, high heat flow (>700mW/m2), andesite, dacite and rhyolite volcanic centres, and many shallow earthquakes defining an 8 km thick seismogenic crust. Whereas the subduction zone continues into northern South Island, the TVZ terminates in a series o f east-east faults immediately to the south of Mount Ruapehu, the southernmost andesite volcano. Preliminary interpretation o f the gravity are consistent with the mapped pattern of active faults and structural geology.