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
The Role of Hydrous Fluids in Fault Processes: An Experimental Study. The proposed project seeks to understand how hydrothermal reactions in fault zones affect various physical properties such as fault strength and permeability. The project will be conducted by performing high pressure experiments which simulate natural conditions. I will also develop new analytical techniques to characterize the microstructural evolution of faults, with a focus on understanding how any changes alter the hydrolo ....The Role of Hydrous Fluids in Fault Processes: An Experimental Study. The proposed project seeks to understand how hydrothermal reactions in fault zones affect various physical properties such as fault strength and permeability. The project will be conducted by performing high pressure experiments which simulate natural conditions. I will also develop new analytical techniques to characterize the microstructural evolution of faults, with a focus on understanding how any changes alter the hydrologic behaviour of the fault. This study will shed much needed information related to the mechanisms of earthquake nucleation, and to the formation mechanism of fault-hosted gold deposits.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
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
Theoretical and experimental study of elastic properties of porous media permeated by aligned fractures. The aim of the project is to develop a theoretical model for the elastic properties of fractured porous reservoir rocks, taking into account the wave-induced fluid flow between pores and fractures. This will be done by theoretical analysis based on the model of fractures as planes of discontinuity in porous rock, and on the theory of wave propagation in anisotropic porous media. The theoretic ....Theoretical and experimental study of elastic properties of porous media permeated by aligned fractures. The aim of the project is to develop a theoretical model for the elastic properties of fractured porous reservoir rocks, taking into account the wave-induced fluid flow between pores and fractures. This will be done by theoretical analysis based on the model of fractures as planes of discontinuity in porous rock, and on the theory of wave propagation in anisotropic porous media. The theoretical model will be verified using numerical simulations and ultrasonic measurements made on synthetic porous and fractured samples. The results are expected to benefit seismic exploration and the production of oil and gas in fractured reservoirs.Read moreRead less