Diagram of geothermal gases rising to surface. Image / Supplied
Diagram of geothermal gases rising to surface. Image / Supplied
How does the Rotorua geothermal field release 1000 tonnes of carbon dioxide into the atmosphere every day?
This is one of the questions at the centre of a three-year research project awarded almost $1 million in funding this month.
A team of seven scientists will be led by Taupō based GNS Science geothermal geologist Isabelle Chambefort from March next year.
GNS Science geothermal geologist Dr Isabelle Chambefort. Photo / Supplied
Chambefort's hypothesis is that geothermal gases originate from eight or more kilometres below ground and reach the surface via weaknesses in the Earth's crust.
If this is proven, it will challenge the view that they come from shallower depths about 5km underground.
Geothermal gases are mainly made up of carbon dioxide.
Aerial view of the boardwalk and geothermal lake in Kuirau Park. Photo / File
Chambefort told the Rotorua Daily Post the carbon dioxide output from the Rotorua geothermal field was measured in the early 2000s, as part of Cynthia Werner and Carlo Cardellini's research published in the scientific journal Geothermics in 2006.
Diagram of geothermal gases rising to surface. Image / Supplied
"This is part of the natural volcanic processes that happen all over the world, including under the sea. The Taupō-Rotorua area hosts large volcanic caldera systems that emit volcanic gas naturally, in the same way White Island or Ruapehu volcanoes are 'breathing'."
Chambefort said her research team would measure the gas flows to detect their origin, how they are transported and how the gases interact.
Te Puia's Papakura Geyser in Rotorua. Photo / File
The team will also analyse the gases' isotypes, the atoms that have the same number of protons but different numbers of neutrons.
"The source, flux, and cycle of CO2 in arc settings is a global research area because it has implications for Earth's climate and habitability. Outcomes will support New Zealand's low emission economy targets and benefit volcanic hazard monitoring."
Chambefort said her findings could also help "enable New Zealand to increase the use of geothermal energy in a sustainable and environmentally friendly way".
Her research will cover the entire Taupō and Rotorua volcanic zone.
Dr Isabelle Chambefort at GNS Science. Photo / Supplied
Chambefort is now preparing for agreements with stakeholders such as iwi and power generation companies that helped shape her proposal.
The Marsden Fund, administered and managed by the Royal Society Te Apārangi on behalf of the Government, granted $958,000 to the project, one of the top 10 largest grants of 136 awarded by the society this year.
The fund supports high-quality research in science, engineering, maths, social sciences, and humanities and has awarded a total of $85.6m in 2018, an all-time high.
The overall success rate for applicants was 12.4 per cent this year.
Marsden Fund Council member Professor Richard Easther from the University of Auckland is the convener of the earth sciences and astronomy panel that awarded Chambefort her grant.
"Marsden grants are chosen for their ability to tackle big, open-ended questions in science," he said.
"This award was made after two rounds of reviews by a panel of scientists, with input from international experts who read the proposals, and it won out over very strong competition."
