AusLAMP is a collaborative national project to cover Australia with long-period magnetotelluric (MT) data in an approximately 55 km spaced array. Signatures from past tectonothermal events can be retained in the lithosphere for hundreds of millions of years when these events deposit conductive mineralogy that is imaged by MT as electrically conductive pathways. MT also images regions of different bulk conductivity and can help to understand the continuation of crustal domains down into the mantle, and address questions on the tectonic evolution of Australia. The AusLAMP data presented here were collected as part of three separate collaborative projects involving several organisations. Geoscience Australia (GA), the Geological Survey of South Australia, the Geological Survey of New South Wales, the Geological Survey of Victoria, and the University of Adelaide all contributed staff and/or funding to collection of AusLAMP data; GA and AuScope contributed instrumentation. The data cover the Paleo-Mesoproterozoic Curnamona Province, the Neoproterozoic Flinders Ranges, and the Cambrian Delamerian Orogen, encompassing eastern South Australia and western New South Wales and western Victoria. This project represents the first electrical resistivity model to image the entire Curnamona Province and most of the onshore extent of the Delamerian Orogen, crossing the geographical state borders between South Australia, New South Wales and Victoria.

Marine seismic surveys are a fundamental tool for geological mapping, including the exploration for offshore oil and gas resources, but the sound generated during these surveys is an acute source of noise in the marine environment. Growing concern and increasing scientific evidence about the potential impacts of underwater noise associated with marine seismic surveys presents an interdisciplinary challenge to multiple sectors including government, industries, scientists and environmental managers. To inform this issue, Geoscience Australia, in collaboration with Curtin University and CSIRO, published a literature review (Carroll et al. 2017) that summarised 70 peer-reviewed scientific studies that investigated the impacts of impulsive low-frequency sound on marine fish and invertebrates. Here we provide an updated, critical synthesis of recently published data to ensure that the Australian governments’ understanding of the potential impacts of seismic surveys on fisheries and the broader marine environment remains current. A significant body of scientific research into the effects of marine seismic sounds on the marine environment has been undertaken over the past four years and scientific knowledge in this area is continuing to improve. This is partly due to increased sophistication of experimental designs that integrate the controlled aspects of laboratory studies, with field-based (before-after-control-impact) studies. However, there remain several research issues and challenges associated with progressing our understanding of the full impact of marine seismic surveys on fisheries and the marine environment. These include the need to broaden the research to cover a wider range of marine species, and to expand our understanding to impacts at the population and ecosystem scale, rather than the individual organism. There is also a continued need for improved standardisation in terminology and measurement of sound exposure. To address the research gaps and issues, Geoscience Australia recommends measures including: 1) undertaking additional multidisciplinary co-designed scientific research to examine short and long term impacts on important life stages of key species (including protected and commercially important species); 2) gathering robust environmental baselines and time-series data to account for spatiotemporal variability in the marine environment and to help inform management and monitoring; 3) continuing to develop and refine standards for quantifying sound exposure; 4) modelling population and ecosystem consequences, and; 5) further studying the interaction of seismic signals with other stressors to better assess cumulative impacts. If applied these recommendations may advance the scientific evidence-base to better inform stakeholder engagement, environmental impact assessment and management of the potential impacts of seismic surveys on fisheries and the marine environment.

The main part of this map is a Hue-Saturation-Intensity (HSI) image of De-trended Global Isostatic Residual Gravity data (DGIR) based on the B Series of the 2019 Australian National Gravity Grids. This series of grids represent the combination of 1.4 million ground gravity observations stored in the Australian National Gravity Database (ANGD) as of September 2019; 345,000 line km of Airborne Gravity and 106,000 line km of gravity gradiometry data in the National Australian Geophysical Database (NAGD), and the Global Gravity Grid developed at Scripps Institution of Oceanography, University of California at San Diego using data from the United States SIO, NOAA and NGA. The ground and airborne gravity data have been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940’s to the present day. The shading of the image is from the northwest and the colour scale is linear from -500 µm.s-2 (blue) to +500 µm.s-2 (red).

<p>Various gridded images were produced from the NTGS Tanami Region Airborne Magnetic and Radiometric Survey dataset and simultaneously merged into a single grid file. The final grid retains all of the information from the input data and is levelled to the national map compilations produced by Geoscience Australia. <p>The following merged grids are available in this download: <p>• Laser-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Radar-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Total magnetic intensity grid (nT). <p>• Total magnetic intensity grid with variable reduction to the pole applied (nT). <p>• Total magnetic intensity grid with variable reduction to the pole and first vertical derivative applied (nT/m). <p>• NASVD-filtered potassium concentration grid (%). <p>• NASVD-filtered thorium concentration grid (ppm). <p>• NASVD-filtered uranium concentration grid (ppm).

Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the GA310 South West Margin 2D MSS survey were acquired for Geoscience Australia in 2008/2009 as part of the Australian Government's Offshore Energy Security Program. This survey acquired a range of pre-competitive geological and geophysical data that included seismic reflection, gravity, magnetic and swath bathymetry measurements, as well as seafloor dredge samples. A total of 26,000 line-kilometres of magnetic and gravity data were acquired during this survey.

This data collection is comprised of radiometric (gamma-ray spectrometric) surveys acquired across Australia by Commonwealth, State and Northern Territory governments and the private sector with project management and quality control undertaken by Geoscience Australia. The radiometric method measures naturally occurring radioactivity arising from gamma-rays. In particular, the method is able to identify the presence of the radioactive isotopes potassium (K), uranium (U) and thorium (Th). The measured radioactivity is then converted into concentrations of the radioelements K, U and Th in the ground. Radiometric surveys have a limited ability to see into the subsurface with the measured radioactivity originating from top few centimetres of the ground. These surveys are primarily used as a geological mapping tool as changes in rock and soil type are often accompanied by changes in the concentrations of the radioactive isotopes of K, U and Th. The method is also capable of directly detecting mineral deposits. For example, K alteration can be detected using the radiometric method and is often associated with hydrothermal ore deposits. Similarly, the method is also used for U and Th exploration, heat flow studies, and environmental mapping purposes such as characterising surface drainage features. The instrument used in radiometric surveys is a gamma-ray spectrometer. This instrument measures the number of radioactive emissions (measured in counts per second) and their energies (measured in electron volts (eV)). Radiometric data are simultaneously acquired with magnetic data during airborne surveys and are a non-invasive method for investigating near-surface geology and regolith.

The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP): New South Wales (NSW) magnetotelluric survey is a collaborative project between the Geological Survey of New South Wales (GSNSW) and Geoscience Australia. Long period magnetotelluric data are being acquired at around 305 sites on a half degree grid spacing across the state of NSW. <u>Phase one</u> This record outlines the field acquisition, data QA/QC, and data processing methodologies relating to the 224 sites released in phase one. The data are released in EDI format containing impedance estimates and transfer functions for each processed site. <u>Phase two</u> A further 73 EDI format data are released as part of phase two. These data were collected and processed using the same methodology as described in the GA record released as part of phase one.

Airborne electromagnetic (AEM) data measure variations in the conductivity of the ground by transmitting an electromagnetic signal from a system attached to a plane or helicopter. Depending on the AEM system used and the sub-surface conditions, AEM techniques can detect variations in the conductivity of the ground to a depth of several hundred metres. The responses recorded are commonly caused by the presence of electrically conductive materials such as salt or saline water, graphite, clays and sulphide minerals. <b>Value:</b> Data used for interpreting the geologic structure of the subsurface. This work can be used for the assessment of resource potential. <b>Scope:</b> Systematic coverage of large portions of the Australian continent.

<p>The accompanying data package, was released on 30 April 2020 by the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA). <p>The package contains processed data from the “MinEx CRC Cobar Airborne Electromagnetic Survey” that was flown over the Cobar–Lake Cargelligo area of Central West New South Wales . The regional survey was flown at 2.5 and 5 km nominal line spacings and entails approximately 5,900 line kilometres of new geophysical data. The survey was flown in 2019 by New Resolution Geophysics Pty. Ltd. (NRG) using the XCITE® airborne electromagnetic system. NRG also processed the data. <p>The survey also included a further 800 line kilometres of infill flying that was funded by private exploration companies, in certain blocks within the survey area. The data from these infill blocks are not part of this data release due to confidentiality agreements but will be released to the public after a 12 month moratorium. <p>GSNSW commissioned the survey as part of the MinEx Cooperative Research Centre’s (MinEx CRC), the world’s largest mineral exploration collaboration. It brings together industry, government, research organisations and universities to further our understanding of geology, mineral deposits and groundwater resources in areas where rocks aren’t exposed at Earth’s surface. GSNSW is a major participant in the NDI program, committing $16 million to the program over 10 years. In NSW, the program focuses on five areas in the state’s central and far west, where metallic minerals potentially exist under a layer of younger barren geology. These areas are North Cobar, South Cobar, Broken Hill (Mundi), Forbes and Dubbo. <p>GA managed the survey data acquisition and processing contract and the quality control of the survey on behalf of GSNSW. GA also contributed by generating one of the two inversion products included in the data package. <p>The data release package comntains <p>1. A data release package summary PDF document. <p>2. The survey logistics and processing report and XCITE® system specification files <p>3. ESRI shape files for the flight lines and boundary <p>4. KML (Google Earth) files of the flight lines <p>5. Final processed point located line data in ASEG-GDF2 format -final processed dB/dt electromagnetic, magnetic and elevation data -final processed BField electromagnetic, magnetic and elevation data <p>6. Conductivity estimates generated by NRG’s inversion -point located line data output from the inversion in ASEG-GDF2 format -graphical (PDF) multiplot conductivity sections and profiles for each flight line -graphical (JPEG) conductivity sections for each line -georeferenced (PNG) conductivity sections (suitable for pseudo-3D display in a 2D GIS) -GoCAD™ S-Grid 3D objects (suitable for various 3D packages) -Curtain image conductivity sections (suitable 3D display in GA’s EarthSci) -Grids generated from the NRG inversion in ER Mapper® format (layer conductivities, depth slices, elevation slices) -Images generated from the grids above (layer conductivities, depth slices, elevation slices) <p>7. Conductivity estimates generated by Geoscience Australia's inversion -point located line data output from the inversion in ASEG-GDF2 format -graphical (JPEG) conductivity sections for each line -georeferenced (PNG) conductivity sections (suitable for pseudo-3D display in a 2D GIS) -GoCAD™ S-Grid 3D objects (suitable for various 3D packages) -Curtain image conductivity sections (suitable 3D display in GA’s EarthSci) -Grids generated from Geoscience Australia's inversion in ER Mapper® format (layer conductivities, depth slices, elevation slices) -Images generated from the grids above (layer conductivities, depth slices, elevation slices) <p>Directory structure <p>├── report <p>│   ├── line_data <p>│   ├── shapefiles <p>│   ├── kml <p>│   ├── contractor_inversion <p>│   │   ├── line_data <p>│   │   ├── multiplots <p>│   │   ├── sections <p>│   │   ├── georeferenced_sections <p>│   │   ├── gocad_sgrids <p>│   │   ├── earthsci <p>│   │   │   └── MinExCRC_Cobar_AEM_Contractor_Regional <p>│   │   ├── images <p>│   │   │   ├── layers <p>│   │   │   ├── depth_slice <p>│   │   │   └── elevation_slice <p>│   │   └── grids <p>│   │   ├── layers <p>│   │   ├── depth_slice <p>│   │   └── elevation_slice <p>│   └── ga_inversion <p>│   ├── line_data <p>│   ├── sections <p>│   ├── georeferenced_sections <p>│   ├── gocad_sgrids <p>│   ├── earthsci <p>│   │   └── MinExCRC_Cobar_AEM_GA-Inversion_Regional <p>│   ├── images <p>│   │   ├── layers <p>│   │   ├── depth_slice <p>│   │   └── elevation_slice <p>│   └── grids <p>│   ├── layers <p>│   ├── depth_slice <p>│   └── elevation_slice

Collection of Geoscience Australia's high-resolution elevation surveys collected using Light Detection and Ranging (LiDAR) and other instrument systems. <b>Value: </b>Describes Australia's landforms and seabed is crucial for addressing issues relating to the impacts of climate change, disaster management, water security, environmental management, urban planning and infrastructure design. <b>Scope: </b>Selected areas of interest around Australia.