Seismic wavespeeds and attenuation in upper-mantle rocks: a laboratory study of the effect of partial melting. The influence of partial melting on the seismic properties of the Earth's upper mantle will be explored through a laboratory study. Synthetic rock specimens consisting of the upper-mantle mineral olivine and a small proportion of basaltic magma will be prepared and their grain-scale melt distribution will be characterised. The seismic properties of these materials will be measured at ....Seismic wavespeeds and attenuation in upper-mantle rocks: a laboratory study of the effect of partial melting. The influence of partial melting on the seismic properties of the Earth's upper mantle will be explored through a laboratory study. Synthetic rock specimens consisting of the upper-mantle mineral olivine and a small proportion of basaltic magma will be prepared and their grain-scale melt distribution will be characterised. The seismic properties of these materials will be measured at high temperatures and seismic frequencies with novel locally developed equipment. Comparison with melt-free equivalents will allow the influence of the added magma to be quantified, allowing robust interpretation of seismological models of Earth structure with implications for its chemical and dynamical evolution.Read moreRead less
The seismic signature of crustal fluids. Fluids are expected to profoundly modify the seismic properties of the cracked rocks of Earth's upper crust (to depths of about 15 km) but there are so far few relevant laboratory measurements. Through the development and application of novel experimental techniques we plan to build a better laboratory-based understanding of the seismic properties of fluid-saturated crustal rocks. The outcome will be an improved capacity to monitor the presence of fluid ....The seismic signature of crustal fluids. Fluids are expected to profoundly modify the seismic properties of the cracked rocks of Earth's upper crust (to depths of about 15 km) but there are so far few relevant laboratory measurements. Through the development and application of novel experimental techniques we plan to build a better laboratory-based understanding of the seismic properties of fluid-saturated crustal rocks. The outcome will be an improved capacity to monitor the presence of fluids in diverse situations ranging from geothermal power generation and waste disposal to earthquake fault zones. Read moreRead less
High-temperature Elastic Wave Speeds of Mantle Minerals and their Seismological Implications. Laboratory measurements of elastic wave speeds are critical for the interpretation of seismological models for the Earth's deep interior. During the past several years, research groups at ANU and Stony Brook University have separately been proving novel experimental techniques for measurement of the temperature dependence of elastic wave speeds. Now a timely collaboration is proposed in which we would ....High-temperature Elastic Wave Speeds of Mantle Minerals and their Seismological Implications. Laboratory measurements of elastic wave speeds are critical for the interpretation of seismological models for the Earth's deep interior. During the past several years, research groups at ANU and Stony Brook University have separately been proving novel experimental techniques for measurement of the temperature dependence of elastic wave speeds. Now a timely collaboration is proposed in which we would exploit access to similar temperature ranges under two very different pressure regimes to examine the mixed pressure-temperature dependence of wave speeds that is so critical for the inference of chemical composition, mineralogical make-up, and temperature variations within the Earth's mantle.Read moreRead less
Mineral Physics of the Earth's Core. Most information on the nature of Earth's core properties has come from teleseismic studies, which detect weak earthquake-wave signals that have traversed the Earth's deepest interior. These studies have revealed several unusual and enigmatic phenomena in the core, but interpretation of these observations must rely on mineral-physics data on the materials of the core (e.g. iron-based alloys). This project will create a unique world-class ultra-high pressure l ....Mineral Physics of the Earth's Core. Most information on the nature of Earth's core properties has come from teleseismic studies, which detect weak earthquake-wave signals that have traversed the Earth's deepest interior. These studies have revealed several unusual and enigmatic phenomena in the core, but interpretation of these observations must rely on mineral-physics data on the materials of the core (e.g. iron-based alloys). This project will create a unique world-class ultra-high pressure laboratory to obtain such data. By defining the composition and mineralogy of Earth's core, it will place Australia in the forefront of this exciting research field, and will also represent a major national resource for the study of novel materials at extreme conditions.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
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