Deep beneath our feet lies a seething cauldron of molten iron, stirred into complex patterns by escaping heat and the Earth’s rotation. This is the geodynamo – the source of Earth’s magnetic field.
We use the magnetic field to navigate and it protects us from the solar wind. We still don’t understand the origin of the field, but the geological record tells us that it changes its intensity on relatively short timescales and sometimes dramatically reverses its direction.
To define these changing directions and intensities, mathematical models require data from many points of the Earth’s surface, but crucial data from the southwest Pacific is missing. Dr Gillian Turner from Victoria University of Wellington will use a Marsden Fund grant to fill the gap.
Dr Turner and her team propose to gather data recorded by magnetic particles deposited in lake and marine sediments in New Zealand. Archaeological artefacts such as fired pottery also contain magnetic particles and will be part of the study. The outcome will be a detailed history of the southwest Pacific’s magnetic field over the last 10,000 years.
This history will enable a high-resolution tool for dating recent events, such as early settlement of New Zealand and climate change, to be developed. And, by combining their measurements with similar observations from the Northern Hemisphere it is hoped to provide a globally consistent model of Earth’s dynamic magnetic field.
Total Funding: $615,000 over 3 years
Researchers: Dr Gillian Turner, School of Chemical and Physical Sciences, Victoria University of Wellington
Tel: +64 (0)4 463 6478