Alpine fault geothermal finding

Research by a Victoria University of Wellington graduate has improved understanding of how underground hot fluids flow through fractured rocks, which will help in the development of geothermal energy.
A study by Dr Cecile Massiot, who graduated last week with a PhD in geophysics, focused on determining the nature of the cracks or fractures that control the circulation of fluids in the Earth’s crust.
“Identifying the characteristics of those fractures that guide fluids is critical for the exploration and management of geothermal renewable resources, which currently accounts for nearly a quarter of New Zealand’s electricity supply.”
Part of Dr Massiot’s study focused on the fracturing adjacent to the Alpine Fault on the West Coast, where scientists drilled a nearly 900m-deep borehole to measure subsurface conditions. The results of that project, published in Nature, reveal surprisingly high temperatures next to the Alpine Fault and the potential for large geothermal resources in the area.
“Determining the layout of fractures near the Alpine Fault is key to understanding the role fluids play in earthquake processes,” Dr Massiot said.
“The high temperatures found in the borehole also open new opportunities for exploring geothermal resources in Westland.”
Dr Massiot, who is originally from France and came to New Zealand in 2010 to work at GNS Science, also looked at the fracture systems in volcanic rocks found at Mount Ruapehu and the Rotokawa Geothermal Field near Taupo.
Dr Massiot’s research was supervised by Professor John Townend of Victoria’s School of Geography, Environment and Earth Sciences, Professor Andrew Nicol, formerly of GNS Science and now at the University of Canterbury and Dr David McNamara, formerly at GNS Science and now at the National University of Ireland, Galway.