Numerical models of tectonism and geothermal circulation with application to the Taupo Volcanic Zone, New Zealand.

Abstract

This thesis discusses the construction and application of a suite of numerical models that describe tectonic and geothermal processes occurring within the Taupo Volcanic Zone (TVZ) of New Zealand’s Central North Island. The TVZ is an active rift characterised by a two million year history of rhyolitic volcanism, normal faulting and geothermal circulation. These phenomena operate and interact with one another over a variety of spatial and temporal scales; however, they are ultimately controlled by two processes: tectonic extension, and magmatic intrusion at the base of the crust. The first part of this thesis discusses generic two-dimensional stress and deformation in an elastic-plastic-viscous crust that hosts a single normal fault.The second half of the thesis details numerical models that investigate non-stationary behaviour in natural geothermal systems.