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.

This collection includes calibrated time-series data and other products from Geoscience Australia's geomagnetic observatory network in Australia and Antarctica. Data dates back to 1924. <b>Value: </b>These data are used in mathematical models of the geomagnetic field, in resource exploration and exploitation, to monitor space weather, and for scientific research. The resulting information can be used for compass-based navigation, magnetic direction finding, and to help protect communities by mitigating the potential hazards generated by magnetic storms. <b>Scope: </b>Continuous geomagnetic time series data, indices of magnetic activity and associated metadata, Data dates back to 1924.

Segmented time series data for earthquake events. Data are in raw digital counts and have associated instrument metadata for calibration to physical ground-motion measures. These data are used to inform a range of applications in seismic hazard assessment and for assessing the utility of current observatory practice for magnitude assessment. <b>Value: </b>Used in the selection and development of ground-motion models used for seismic hazard purposes. These data also enable the assessment and development of new earthquake magnitude formulae. <b>Scope: </b>Data has been collected on an ad hoc basis, some early digital data dates back to 1989 (i.e. Newcastle earthquake), and the dataset continues to grow as earthquakes of interest occur, or various temporary deployments are rolled out. Instrument metadata is not always known.

Descriptions of and measurements from field sites and samples from geological (including regolith) surveys. <b>Value: </b>Used to constrained surface geology, important in resource exploration and understanding physical environment. <b>Scope: </b>Mapping surveys mainly in Australia, but also in Antarctica, Oceania and south-east Asia.

Magnetotellurics (MT) is a passive geophysical method which uses natural time variations of the Earth's magnetic and electric fields to measure the electrical resistivity of the sub-surface. Electrical resistivity is a bulk property of a volume of Earth material and is associated with factors such as rock composition, porosity and permeability as well as temperature and pressure. The Magnetotelurics (MT) Data Collection includes datasets from The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) and regional-scale MT surveys across the Australian continent. These data were collected by Geoscience Australia in collaboration with the State and Territory Geological Surveys and other partners. <b>Value: </b>Magnetotelluric data to expand the geoscientific understanding of the earth's lithospheric structure and provide new insights into Australia's onshore energy and mineral potential. <b>Scope: </b>AusLAMP is being conducted over multiple years to create a national MT dataset and map lithospheric structure of the Australian continent. MT data have also been acquired for mapping crustal structure and resource potential at regional scale. These data provide valuable information for multi-disciplinary interpretations. To view the magnetotellurics data via the Geoscience Australia internet page click on the following URL: <a href="https://www.ga.gov.au/about/projects/resources/regional-mt-program">https://www.ga.gov.au/about/projects/resources/regional-mt-program</a> For further information about the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) click on the following URL: <a href="https://www.ga.gov.au/about/projects/resources/auslamp">https://www.ga.gov.au/about/projects/resources/auslamp</a>

Parametric dataset of earthquakes in the Australian region, with magnitudes greater than 2.5. Includes records of instrumentally recorded earthquakes and explosions, and earthquake parameters inferred from historic documents. Threshold magnitude of completeness varies spatially and temporally. <b>Value: </b>This data has historic value, and is used in assessment of earthquake hazard, risk and potential impacts from future events. <b>Scope: </b>A catalogue of known historical earthquakes in Australia and adjacent regions.

Collection of field notebooks recording mainly geological observations made by staff of Geoscience Australia (GA) and its predecessors, Bureau of Mineral Resources (BMR) and Australian Geological Survey Organisation (AGSO), while conducting fieldwork between 1930 and 2010. The notebooks are currently being digitised. <b>Value: </b>Historic and scientific significance. Many sites visited are remote and have rarely been revisited. Some notebooks also record observations on fauna and flora. <b>Scope: </b>Geographical scope is largely Australia, pre- and post-Independence Papua New Guinea (PNG), and the Australian Antarctic Territory, but other countries and territories are represented.

Survey Data captured after severe natural hazard events covering a range of hazards with specific attributes. This observational information is used as input data to assessing vulnerability to natural hazard, but is not made available in its raw form. <b>Value: </b>Used to assess impacts from natural disasters and thereby reduce future risks. <b>Scope: </b>Australia, data from Papua New Guinea, Indonesian province of West Sumatra (Padang) and New Zealand

Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The gravity data collection contains both onshore and offshore data acquired on geophysical surveys conducted by Commonwealth, State & NT Governments and the private sector. <b>Value: </b>Gravity used to infer (model) the presence and position of different rock types in the subsurface. Used in resource assessment <b>Scope: </b>Australia continent and some data from marine surveys in region

Geometric representations of major surface water features of Australia, such as rivers, lakes, reservoirs, dams, canals and catchments. Also includes hydrologic features such as catchment boundaries and drainage basins. <b>Value:</b> This data is not authoritative, but represent a valuable resource for visualisation, decision support and planning activities. <b>Scope:</b> This is a National dataset at resolution relevant for presentation of regional spatial data such as digital maps.