Geoscience Australia (GA) has recently completed two regional-scale Airborne Electromagnetic (AEM) surveys: one in the Paterson Region, WA; and the other in the Pine Creek region, NT. These surveys provide AEM data at line spacings of 200 m to 6 km covering an area greater than 110 000 km2. The surveys were designed to promote more detailed investigations by the mineral exploration industry. An inherent risk in using AEM surveys is that the depth of penetration of the primary electromagnetic field is highly variable. Although forward modelling is undertaken before the AEM campaign, the depth to which we can reliably invert the AEM signal to generate conductivity models is not known until after the survey is flown. In order to estimate the penetration depth of the AEM surveys, we calculate the depth of investigation (DOI) based on the GA layered-earth inversion algorithm, which is influenced by both conductivity measurements and reference model assumptions. We define the DOI as the maximum depth at which the inversion is influenced more by the conductivity data than the reference model. We present the DOI as a 2D grid across both the Paterson and Pine Creek AEM surveys. Labelled the 'AEM go-map', the DOI grid helps to promote AEM exploration by decreasing risk when industry undertakes follow-up surveys within these regions.

Between the 31st of March 2013 and the 15th of May 2013, Fugro Airborne Surveys Pty. Ltd., (FAS, now known as CGG Aviation (Australia) Pty Ltd) undertook a TEMPEST® airborne electromagnetic and magnetic survey over the South West Coastal Plain and the South Coast areas of Western Australia. There were four separate project areas: (1) Swan Coastal Plain, (2) Scott Coastal Plain, (3) Albany, (4) Esperance. The survey is designed to map groundwater resources and assess aquifer sustainability in four separate areas of southern WA. The survey areas are located in: 1. Esperance: Traverses spaced 300 & 600 metres apart in a north-south direction at 120 metres above ground level totalling 1,133 line km. 2. Albany: Traverses spaced 300 & 600 metres apart in a north-south direction at 120 metres above ground level totalling 2,163 line km. 3. Scott Coastal Plain: Traverses spaced 600 metres apart in a ne-sw direction at 120 metres above ground level totalling 2,980 line km. 4. Swan Coastal Plain: Traverses spaced 600 metres apart in a nw-se direction at 120 metres above ground level totalling 2,303 line km. The total coverage of the survey amounted to 8,579 line kilometres. The survey was flown using a Shorts Skyvan (SC3-200) aircraft, registration VH-WGT, owned and operated by FAS. The survey was commissioned by the Western Australia Department of Water, and was managed by Geoscience Australia. The Survey received funding from the WA Government's Royalties for Regions program to assess, plan and investigate regional water availability in Western Australia. The data release includes the final contractor supplied datasets. The data are available from Geoscience Australia's web site free of charge. Each data package includes: 1. Point-located electromagnetic data with associated position, altimeter, orientation, magnetic, and derived ground elevation data. These data are in ASCII column format with associated ASEG-GDF2 header files. 2. Point-located conductivity estimates derived using the EM Flow® conductivity depth imaging (CDI) algorithm with associated position, altimeter, magnetic, and derived ground elevation data. Data include the conductivity estimate for each 5 m interval and selected depth slices. These data are in ASCII column format with associated ASEG-GDF2 header files. 3. Gridded data, at 60 or 120 m cell size, for the conductivity depth slices derived from the EM Flow® CDI data, magnetics and elevation data in ER Mapper® binary raster grid format with associated header files. 4. Graphical multiplots, in PDF format, for each flight line showing EM Flow® CDI sections and profiles of electromagnetic data, magnetics, monitors, height and orientation data. 5. Operations Report. 6. Metadata and License files.

In 2008, the Ord Irrigation Cooperative commissioned an airborne electromagnetics (AEM) survey of the ORIA Stage 1 and 2 areas to identify, quantify and understand any potential salinity risks in the current Ord irrigation area and the parts of the catchment that have been identified as potential future irrigation sites or potentially impacted by future irrigation. The project has been funded by the Australian and Western Australian governments through the National Action Plan for Salinity and Water Quality. Geoscience Australia and CSIRO were contracted to carry out the analysis and interpretation of the AEM dataset, and produce customised interpretation products. Some of the more specific questions it was hoped to address included: - Are we at risk of salinity in the Ord Catchment? - If so what areas are at the greatest risk? - Where can we target management to reduce this risk? - How can we plan future development to minimise salinity risk and maximise longevity of projects? The areas surveyed include the current Stage 1 Ord Irrigation Area, Stage 2 Irrigation Area (including Weaber and Knox Plains and Carlton Hill - Parry's Lagoon Conservation Area. The inclusion of undeveloped land in this survey is because the technology provides the opportunity to ensure any future irrigation development is guided by the best available information on soil type, aquifer quality and location and salinity risk. The information generated by this project will be publicly available and can be used for such things as: - Identifying leaky areas in the landscape that may require more concentrated management or can be designated for more suitable land use; - Where salt is stored in the landscape and at what depth, and where in the landscape it may influence plant growth; - Provide new constraints on the connectivity of aquifer systems in 3D across the ORIA and enable the construction of more realistic hydrogeological models to improve surface and groundwater management.

A guide to the use of AEM geophysics for mapping SWI in coastal landscapes and karstic aquifer systems in Australia. The project was funded by the National Water Commission (NWC), with significant in-kind resources and funding provided by Geoscience Australia (GA) and the Northern Territory Department of Resources, Environment, Tourism, Arts and Sports (NRETAS).

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.

During 2008 and 2009, and under the Australian Government's Onshore Energy Security Initiative, Geoscience Australia acquired airborne electromagnetic (AEM) data over the Pine Creek Orogen of the Northern Territory. The survey area was split into three areas for acquisition. VTEM data was acquired in the Kombolgie area east of Kakadu National Park between August and November 2008. TEMPEST data was acquired west of Kakadu National Park with the area split in two to facilitate the use of two aircraft: the Woolner Granite area in the north (this data set) was acquired between October and December 2008; and the Rum Jungle area adjoining to the south, was acquired between October 2008 and May 2009. The main purpose of the surveys was to provide additional geophysical/geological context for unconformity style uranium mineral systems and thereby promote related exploration. The survey data will also provide information on depth to Proterozoic/Archean basement, which is of general interest to explorers, and will be used as an input into ground water studues in the region.

During 2008 and 2009, and under the Australian Government's Onshore Energy Security Initiative, Geoscience Australia acquired airborne electromagnetic (AEM) data over the Pine Creek Orogen of the Northern Territory. The survey area was split into three areas for acquisition. VTEM data was acquired in the Kombolgie area east of Kakadu National Park between August and November 2008. TEMPEST data was acquired west of Kakadu National Park with the area split in two to facilitate the use of two aircraft: the Woolner Granite area in the north was acquired between October and December 2008; and the Rum Jungle area (this data set) adjoining to the south, which was acquired between October 2008 and May 2009. The main purpose of the surveys was to provide additional geophysical/geological context for unconformity style uranium mineral systems and thereby promote related exploration. The survey data will also provide information on depth to Proterozoic/Archean basement, which is of general interest to explorers, and will be used as an input into ground water studues in the region.

Borehole induction conductivity data, commonly referred to as conductivity logs, were acquired from 20 boreholes in the Frome region of South Australia, during July-August 2010, in support of the Frome airborne electromagnetic (AEM) survey managed by Geoscience Australia (GA). The conductivity logs were used to assist in generating reference models for geophysical inversions of the AEM data, and to provide an independent dataset for assessing the inversion results. The Frome AEM survey was acquired using the Fugro Airborne Surveys (FAS) TEMPEST fixed wing time-domain electromagnetic (TEM) AEM system. The acquisition and processing of data were carried out by FAS under contract to GA. The geophysical investigations were designed to deliver reliable, pre-competitive AEM data and scientific analysis of the energy resource potential of the Frome region of South Australia, including the flanks of the Northern Flinders Ranges, the Frome Embayment, the Olary Ranges and the northwestern Murray Basin. The Frome AEM survey covers a total area of 95,000 km2 and was flown between 22 May and 2 November 2010.

During 2007 and 2008 and under the Australian Government's Onshore Energy Security Initiative, Geoscience Australia acquired airborne electromagnetic (AEM) data over the Paterson Province of Western Australia. At the time, interested exploration companies were offered the opportunity to infill the regional survey. The data in this release were acquired from two infill areas, S2 and S3, for Western Areas NL. The main purpose of the regional survey was to provide additional geophysical/geological context for unconformity and palaeochannel style uranium mineral systems and thereby promote related exploration. The survey data will also provide information on depth to basement, which is of general interest to explorers, and will be used as an input into a ground water evaluation of the region.

In 2007 a RESOLVE frequency domain airborne electromagnetic survey was flown over and adjacent to a stretch of the River Murray along the western border separating Victoria and New South Wales, Australia. The survey was commissioned by the Australian Government Department of Agriculture, Fisheries and Forestry through the Bureau of Rural Sciences and funded under the National Action Plan for Salinity and Water Quality.