Geophysical Study of the Northern Part of Te Kopia Geothermal Field, Taupo Volcanic Zone, New Zealand

Abstract

Geophysical surveys were carried out in 1993and 1997 to investigate the northern part of the Te field (central North Island of New Zealand). The surveys of electrical resistivity using small array spacings of 60 m and 30 m),Schlumberger vertical electrical sounding ground magnetic survey,and temperature measurements at 1m depth. The a zone of warm ground associated with low-resistivity and low-magnetic gradient extending from the North Lakes (main surface area) and Road Springs, through the Murphy Hill area (mud craters and steaming ground), towards the Murphy's Farm Springs near the northern of the field. This active alteration zone probably indicates a path of near thermal waters which is controlled by a set of small, Such a shallow hydrology of thermal waters is sensitive to minor movements of the faults which can trigger thermal perturbations such as those occurred in late 1993 early 1994.