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  • Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Barr Creek - Gunbower study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

  • The Pine Creek AEM survey was flown over the Pine Creek Orogen in the Northern Territory during 2008 and 2009 as part of the Australian Government's Onshore Energy Security Program at Geoscience Australia (GA). The survey provides pre-competitive data for enhancing uranium and other mineral exploration. Flight line spacing was 1666 m and 5000 m covering an area of 74,000 km2 (roughly the size of Tasmania) which hosts several uranium deposits, including the Ranger Uranium Mine, Rum jungle, Ranger and Nabarlek. The region is also prospective for metals including copper, lead, zinc, gold, tin, rare earths, tantalum, tungsten, molybdenum and nickel. The Pine Creek AEM survey comprises three areas: Kombolgie to the east of Kakadu National Park; Woolner Granite near Darwin; and, Rum Jungle to the west of Kakadu National Park. Collaboration with the National Water Commission and eight private infill companies brought an additional investment of approximately $1 m into the survey, with follow-up exploration equal to or exceeding this amount. The Woolner Granite and Rum Jungle survey area data were acquired using the TEMPEST fixed wing AEM system. The acquisition and processing were carried out by Fugro Airborne Surveys Pty. Ltd., under contract to GA. The Woolner Granite and Rum Jungle surveys were flown between August 2008 and May 2009 and the data were publicly released by GA in July and September 2009 respectively. In the Kombolgie survey area, the data were acquired a by Geotech Airborne Pty. Ltd. using the VTEM helicopter AEM system. The survey was flown between August and November of 2008, and additional calibration flights relating to the survey were flown in April 2009. The Kombolgie data were publicly released by GA in December 2009.

  • The use of airborne electromagnetics (AEM) for hydrogeological investigations often requires high resolution data. Optimisation of AEM data therefore requires careful consideration of AEM system suitability, calibration, validation and inversion methods. In the Broken Hill managed Aquifer Recharge (BHMAR) project, the helicopter-borne SkyTEM transient EM system was selected after forward modelling of system responses and assessment of test line data over potential targets. The survey involved acquisition of 31,834 line km of data over an area of 7,500 km2 of the River Darling Floodplain. Initial FAI inversions provided within 48 hours of acquisition were used to target 100 sonic and rotary mud holes for calibration and validation. A number of different (Laterally and Spatially Constrained) inversions of the AEM data were carried out, with refinements made as additional information on vertical and lateral constraints became available. Finally, a Wave Number Domain Approximate Inversion procedure with a 1D multi-layer model and constraints in 3D (including boreholes), was used to produce a 3D conductivity model. This inversion procedure only takes days to run, enabling rapid trialling to select the most appropriate vertical and horizontal constraints. Using this approach has produced reliable, quantitative estimates of the 3D conductivity structure, and enabled identification of a diverse range of MAR options and groundwater resources. The hydrogeological complexity revealed by AEM mapping greatly improves the parameterisation of groundwater models, and provides a framework for understanding complex hydrogeological and hydrogeochemical processes that are critical to assessment of a range of MAR, surface water and groundwater extraction options.

  • Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Liparoo - Robinvale study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

  • Airborne electromagnetic (AEM) data are being acquired by Geoscience Australia (GA) under the Australian Government's Onshore Energy Security Program (OESP) in areas considered to have potential for uranium or thorium mineralisation. In contrast to deposit-scale investigations carried out by industry these surveys are designed to reveal new geological information at a regional scale. The Frome AEM survey shown in Figure 1 was flown by Fugro Airborne Surveys for GA, using the TEMPESTTM time-domain system. The survey was conducted with the aims of reducing exploration risk, stimulating exploration investment and enhancing prospectivity within the region primarily for uranium, but also for other commodities including copper, gold, silver, lead, zinc, iron ore and potable groundwater. The Frome AEM survey was primarily designed to be a regional mapping program for mapping surface and subsurface geological features that may be associated with sandstone-hosted uranium systems. The data are also capable of being interpreted for landscape evolution studies within the flanks of the tectonically active Curnamona Province and Flinders Ranges of South Australia. In this article we present an enhanced set of conductivity estimates which are now available from the GA website free of charge. These conductivity estimates reveal new geological information

  • Phase 3a of the Broken Hill Managed Aquifer Recharge (BHMAR) project is tasked with assessing whether a sustainable ground water extraction approach, including MAR, is a feasible option for securing Broken Hill's water supply in times of drought. More specifically, the project is charged with determining, with a defined level of confidence, whether at least 3 years water supply (~30 GL), at a similar salinity to that already available for Broken Hill would be available at all times through these new arrangements. This interim report documents the preliminary findings of the Phase 3a study, which is focussed on a priority target immediately south of Menindee.

  • A brief summary fo the highlights of the Paterson AEM survey and planned future work of Geoscience Australia's Airborne EM Project.

  • Identification of groundwater-dependent (terrestrial) vegetation, and assessment of the relative importance of different water sources to vegetation dynamics commonly involves detailed ecophysiological studies over a number of seasons or years. However, even when groundwater dependence can be quantified, results are often difficult to upscale beyond the plot scale. Consequently, quicker, more regional mapping approaches have been developed. These new approaches utilise advances in computation geoscience, and remote sensing and airborne geophysical technologies. This study, undertaken in the semi-arid Darling River Floodplain in N.S.W., Australia, combines Landsat Normalised Difference Vegetation Index (NDVI) time series data with hydrogeological, hydrogeochemical and hydrogeophysical data to assess the relative importance of hydrological processes and groundwater characteristics. The first stage in the study combined high-resolution vegetation structural mapping derived from LiDAR data (Canopy Digital Elevation Model and Foliage Projected Cover), with 23 years of Landsat time-series data. Statistical summaries of Normalised Difference Vegetation Index values were generated for each spatially continuous vegetation structural class for each Landsat scene (e.g. stand of closed forest). This has enabled long-term temporal changes in vegetation condition to be assessed against different water regimes (drought, local rainfall, river bank full, overbank flow, and lake filling), and groundwater dependent vegetation to be identified. The second stage involved integration with airborne electromagnetics (AEM), hydrogeology and hydrogeochemistry. This has shown that the deeper (>25m), semi-confined aquifer is only rarely important to vegetation dynamics, with the shallow unconfined aquifer and river lateral bank recharge zones being of greater importance.

  • Short article describing a new method of defining depth of investigation for airborne electromagnetic surveys

  • Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Nangiloc - Colignan study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Group's assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.