Measuring underground electromagnetic fields
Finding minerals in the ground is no longer the gamble of digging and panning for gold it used to be. We now use measurements of electromagnetic fields to discover what’s below the surface.
One geophysical method that uses electromagnetic field measurements is called magnetotellurics. It allows scientists and resource companies to map deep underground structures and detect useful resources in Australia’s crust.
Professor Graham Heinson from the University of Adelaide is working with NCI to build an easy to use dataset of Australian magnetotelluric measurements collected by the research community.
The measurements include the size, frequency and orientation of signals in the ground. These measurements are complex, easily affected by the chemistry and temperature of various underground ores and deposits, as well as by water in pores near the surface.
Professor Heinson is leading the team bringing this data together in an accessible format as part of the broader Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP), run as a collaboration between AuScope, GA and the State and Territory Geological Surveys. The data and metadata will be intuitively organised and integrated, stored in relevant and compatible formats, and easier to find and access.
By rescuing old data and securing new data in this high-quality archival system, Dr Heinson is ensuring that we can build on the many diverse data collection programs from the last thirty years.
“The data we gathered 30 years ago is still valuable today, so there’s no reason that today’s data won’t still be valuable into the future,” he says.
The Adelaide University AusLAMP dataset, stored at NCI, is recognised as a high-profile and high-quality dataset with big international impact. Industry and academic groups alike have shown significant interest in using the dataset.
For the big resource extraction companies, the only economical way to discover new deposits in the future is to use these scientific techniques.
Understanding the geology of a region also gives information about possible earthquake and volcanic activity, clues about aquifers and ground drainage, and the natural history of our continent.