Resistivity of typical rocks at crustal pressure and temperature conditions from combined laboratory and magnetotelluric measurements. Magnetotelluric surveys are playing an increasing role in Australian geoscience, including academic research, data collected by geological surveys (including a role in Geoscience Australia's $58.9 million Onshore Energy and Security Program), mineral exploration and geothermal exploration. This project will enable the results of these surveys to be interpreted mo ....Resistivity of typical rocks at crustal pressure and temperature conditions from combined laboratory and magnetotelluric measurements. Magnetotelluric surveys are playing an increasing role in Australian geoscience, including academic research, data collected by geological surveys (including a role in Geoscience Australia's $58.9 million Onshore Energy and Security Program), mineral exploration and geothermal exploration. This project will enable the results of these surveys to be interpreted more accurately and meaningfully by constraining the expected resistivities of crustal rocks at various pressures and temperatures. This research is vital if the investment currently being put into MT surveys is to be capitalized upon. Read moreRead less
Airborne electromagnetic estimation of groundwater quality and distribution in the top 100m of the earth. This research will develop processing methodology to predict groundwater concentration and quality in the top 100m of the earth, using continuously sampled airborne electromagnetic data. The method to be developed will process received responses to separate and identify propagation delays, distinct from the usual diffusive delays caused by shallow conductive materials. The extracted propagat ....Airborne electromagnetic estimation of groundwater quality and distribution in the top 100m of the earth. This research will develop processing methodology to predict groundwater concentration and quality in the top 100m of the earth, using continuously sampled airborne electromagnetic data. The method to be developed will process received responses to separate and identify propagation delays, distinct from the usual diffusive delays caused by shallow conductive materials. The extracted propagation delays then predict ground moisture content. With proposed changes to transmitter hardware, we can also achieve improved shallow resolution of conductive structures, such as shallow saline groundwater layers. However, the new method will pioneer the remote detection of fresh waters.Read moreRead less
Accurately locating the depth and distribution of saline waters with improved shallow conductivity sounding using broadcast radio transmissions. Conductivity meters such as the EM31 are in routine use for mapping shallow salinity, but provide no depth information. This research will provide methodology using broadcast radio transmissions to additionally provide the depth information needed to interpret shallow layering and inhomogeneity. Instruments will initially be tested on the ground, but a ....Accurately locating the depth and distribution of saline waters with improved shallow conductivity sounding using broadcast radio transmissions. Conductivity meters such as the EM31 are in routine use for mapping shallow salinity, but provide no depth information. This research will provide methodology using broadcast radio transmissions to additionally provide the depth information needed to interpret shallow layering and inhomogeneity. Instruments will initially be tested on the ground, but are ultimately intended to be applied from the air, where existing systems have no resolution in the top 5 m. The method will provide crucial root-zone data for precision agriculture in salt-affected areas, and address accurate salt mapping issues in the major efforts to combat Australia's salinity problems.Read moreRead less
New developments in 3D electrical resistivity imaging of the shallow subsurface. This project is concerned with developing improved procedures for electrical imaging of hidden geological features in the subsurface. These techniques are required to solve urgent problems associated with important issues, such as natural hazards, disposal of dangerous waste, groundwater and construction of major buildings and tunnels. The project will develop new hardware, software and interpretation aids, as well ....New developments in 3D electrical resistivity imaging of the shallow subsurface. This project is concerned with developing improved procedures for electrical imaging of hidden geological features in the subsurface. These techniques are required to solve urgent problems associated with important issues, such as natural hazards, disposal of dangerous waste, groundwater and construction of major buildings and tunnels. The project will develop new hardware, software and interpretation aids, as well as providing postgraduate training in an area of vital national importance.Read moreRead less
Three-dimensional magnetotelluric imaging of lithospheric-scale mineral systems from source to deposit. Geochemical studies indicate that world-class mineral deposits are partly sourced from fluids emerging from Earth's mantle and lower crust. Finding major mineral deposits in the future will therefore require knowledge of which parts of the crust and mantle yield the most prospective locations. However, there are few methods that can image deep Earth resources, and these can be very expensive ....Three-dimensional magnetotelluric imaging of lithospheric-scale mineral systems from source to deposit. Geochemical studies indicate that world-class mineral deposits are partly sourced from fluids emerging from Earth's mantle and lower crust. Finding major mineral deposits in the future will therefore require knowledge of which parts of the crust and mantle yield the most prospective locations. However, there are few methods that can image deep Earth resources, and these can be very expensive. We propose to develop the magnetotelluric method as a low-cost and rapid approach for delineating 3D information on deep mineral systems beneath existing major deposits, and adapting this to explore in greenfield locations.Read moreRead less
Three-dimensional magnetotelluric and controlled-source electromagnetic modelling and inversion in isotropic and anisotropic media with Gaussian Quadrature Grids. Electromagnetic methods are widely used by geophysicists in many applications, including mineral, petroleum and geothermal exploration, environmental and groundwater characterisation, and in imaging of Earth and other planets. Large data-sets are routinely collected, but to interpret these carefully we need efficient computer modellin ....Three-dimensional magnetotelluric and controlled-source electromagnetic modelling and inversion in isotropic and anisotropic media with Gaussian Quadrature Grids. Electromagnetic methods are widely used by geophysicists in many applications, including mineral, petroleum and geothermal exploration, environmental and groundwater characterisation, and in imaging of Earth and other planets. Large data-sets are routinely collected, but to interpret these carefully we need efficient computer modelling tools that incorporate the complexity of the subsurface. We will develop a new computer algorithm that uses an innovative approach to model the Earth in three dimensions. Computer codes will be available through the national AuScope infrastructure facilities, so that researchers will have free access to algorithms, largely for the first time, to better interpret their data.Read moreRead less
Rapid approximate imaging of electromagnetic data acquired using multichannel distributed acquisition systems. This project will investigate techniques for rapid, multidimensiuonal imaging of electromagnetic data acquired using modern multichannel distributed acquisition systems. This research will provide high-resolution images of buried ore deposits at greater depths than is possible using current instruments and processing techniques.
Optimisation of Signal-to-Noise Ratio in Electrical and Electromagnetic Investigations. Electrical and electromagnetic geophysical methods have been used extensively for mineral exploration, and are developing a role in salinity mapping and contaminant identification. To enhance the utility of such methods for very shallow targets (in the case of salinity) and deep targets (minerals beneath regolith)improved signal processing methods are required. The project involves the development of time-ser ....Optimisation of Signal-to-Noise Ratio in Electrical and Electromagnetic Investigations. Electrical and electromagnetic geophysical methods have been used extensively for mineral exploration, and are developing a role in salinity mapping and contaminant identification. To enhance the utility of such methods for very shallow targets (in the case of salinity) and deep targets (minerals beneath regolith)improved signal processing methods are required. The project involves the development of time-series processing techniques using robust-statistical methods and remote-referencing to improve signal-to-noise data quality. Instrumentation hardware and software developments are required for in-field data acquisition and interpretation, applied to direct current (DC) resistivity, induced polarisation (IP) and time-domain EM (TEM).Read moreRead less