Work Package II: Testing the electrical conductivity of the ground and subsurface around New Zealand. Which powerlines and transformers are affected by geomagnetically induced currents (GIC) is very much dependent on the electrical structure of the Earth as this dictates the orientation and size of the induced voltages which drive these currents. The electrical conductivity of the Earth at a location can be measured using a technique called magnetotelluric sounding (MT) in which variations in induced currents in the ground are measured and related to simultaneously measured variations in the earth’s magnetic field. GNS Science and VUW have made many such measurements over significant portions of New Zealand, however the Otago/Southland and Northland regions have yet to be surveyed and are the focus of this work package. In particular, given the proximity to the auroral zone, understanding the structure in Otago/Southland is critical to modelling how magnetic storms may impact the power network.
        Leaders: Wiebke Heise (GNS), Malcolm Ingham (VUW) 

Work Package VI: There is evidence that transformers, a critical part of the electricity grid, are deteriorated by repeated geomagnetic disturbances. Transpower is New Zealand’s state-owned enterprise responsible for power transmission. Tests will be done on Transpower’s transformers, simulating geomagnetic storms by injecting DC current into operational transformers, and undertaking dissolved gas analysis to determine the levels of deterioration and damage.
        Leaders: Andrew Lapthorn (Canterbury University)