This the top-level collection record for all of Geoscience Australia's public vocabularies. The vocabularies are all formulated using the SKOS (Simple Knowledge Organization System) information model and delivered both as machine-readable Resource Description Framework (RDF) data and also as HTML web pages. Each vocabulary is delivered individually as RDF & HTML data and all vocabularies are linked to from both GA's vocabularies index static web page and also from the Australian National Data Service (ANDS)'s Research Vocabularies Australia (RVA) portal. All vocabularies, collections of concepts within vocabularies and individual concepts are identified with URI persistent identifiers of the form: http://pid.geoscience.gov.au/def/voc/ga/{VOCABULARY-KEY}/{COLLECTION-OR-CONCEPT-NAME} This means that you can access all the information about a vocabulary, a collection or a concept directly by entering that URI into your web browser.

Wind multipliers are factors that transform wind speeds over open, flat terrain (regional wind speeds) to local wind speeds that consider the effects of direction, terrain (surface roughness), shielding (buildings and structures) and topography (hills and ridges). During the assessment of local wind hazards (spatial significance in the order 10's of metres), wind multipliers allow for regional wind speeds (order 10 to 100's of kilometres) to be factored to provide local wind speeds. <b>Value: </b>The wind multiplier data is used in modelling the impacts (i.e. physical damage) of wind-related events such as tropical cyclones (an input for Tropical Cyclone Risk assessment), thunderstorms and other windstorms. <b>Scope: </b>Includes terrain, shielding and topographic multipliers for national coverage. Each multiplier further contains 8 directions.

The Topographic Position Index measures the topographic slope position of landforms by comparing the mean elevation of a specific neighbourhood area with the elevation value of a central cell. This is done for every cell or pixel in the digital elevation model (DEM) to derive the relative topographic position (e.g. upper, middle and lower landscape elements). Ruggedness informs on the roughness of the surface and is calculated as the standard deviation of elevations. Both these terrain components are used to generate a multi-scale topographic index over the Australian continent using the algorithm developed by Lindsay, J, B., Cockburn, J. M. H. and Russell, H. A. J., 2015. An integral image approach to performing multi-scale topographic position analysis, Geomorphology, 245, 51-61. Topographic position is captured across three spatial scale and display as a ternary image. The ternary image reveals a rich representation of nested landform features with broad application to geomorphological and hydrological process understanding and mapping of regolith and soils. <b>Value: </b>Broad application in understanding geomorphological and hydrological processes and in mapping regolith and soils over the Australian continent. Can be used as inputs into geospatial modelling and machine learning <b>Scope: </b>The dataset is national. The algorithm can be run on any digital elevation gridded dataset.

Radiogenic isotopes decay at known rates and can be used to interpret ages for minerals, rocks and geologic processes. Different isotopic systems provide information related to different time periods and geologic processes, systems include: U-Pb and Ar/Ar, Sm-Nd, Pb-Pb, Lu-Hf, Rb-Sr and Re-Os isotopes. The GEOCHRON database stores full analytical U-Pb age data from Geoscience Australia's (GA) Sensitive High Resolution Ion Micro-Probe (SHRIMP) program. The ISOTOPE database is designed to expand GA's ability to deliver isotopic datasets, and stores compiled age and isotopic data from a range of published and unpublished (GA and non-GA) sources. OZCHRON is a depreciated predecessor to GEOCHRON and ISOTOPE, the information once available in OZCHRON is in the process of migration to the two current databases. The ISOTOPE compilation includes sample and bibliographic links through the A, FGDM, and GEOREF databases. The data structure currently supports summary ages (e.g., U-Pb and Ar/Ar) through the INTERPRETED_AGES tables, as well as extended system-specific tables for Sm-Nd, Pb-Pb, Lu-Hf and O- isotopes. The data structure is designed to be extensible to adapt to evolving requirements for the storage of isotopic data. ISOTOPE and the data holdings were initially developed as part of the Exploring for the Future (EFTF) program - particularly to support the delivery of an Isotopic Atlas of Australia. During development of ISOTOPE, some key considerations in compiling and storing diverse, multi-purpose isotopic datasets were developed: 1) Improved sample characterisation and bibliographic links. Often, the usefulness of an isotopic dataset is limited by the metadata available for the parent sample. Better harvesting of fundamental sample data (and better integration with related national datasets such as Australian Geological Provinces and the Australian Stratigraphic Units Database) simplifies the process of filtering an isotopic data compilation using spatial, geological and bibliographic criteria, as well as facilitating 'audits' targeting missing isotopic data. 2) Generalised, extensible structures for isotopic data. The need for system-specific tables for isotopic analyses does not preclude the development of generalised data-structures that reflect universal relationships. GA has modelled relational tables linking system-specific Sessions, Analyses, and interpreted data-Groups, which has proven adequate for all of the Isotopic Atlas layers developed thus far. 3) Dual delivery of 'derived' isotopic data. In some systems, it is critical to capture the published data (i.e. isotopic measurements and derived values, as presented by the original author) and generate an additional set of derived values from the same measurements, calculated using a single set of reference parameters (e.g. decay constant, depleted-mantle values, etc.) that permit 'normalised' portrayal of the data compilation-wide. 4) Flexibility in data delivery mode. In radiogenic isotope geochronology (e.g. U-Pb, Ar-Ar), careful compilation and attribution of 'interpreted ages' can meet the needs of much of the user-base, even without an explicit link to the constituent analyses. In contrast, isotope geochemistry (especially microbeam-based methods such as Lu-Hf via laser ablation) is usually focused on the individual measurements, without which interpreted 'sample-averages' have limited value. Data delivery should reflect key differences of this kind. <b>Value: </b>Used to provide ages and isotope geochemistry data for minerals, rocks and geologic processes. <b>Scope: </b>Australian jurisdictions and international collaborative programs involving Geoscience Australia

Digital Elevation Model data record the terrain height variations from the processed point-located data recorded on an airborne geophysical survey. The aircraft altimeter data records the height of the aircraft above the ground and the aircraft GPS records the height of the aircraft above the ellipsoid. Subtracting the two values enables the height of the terrain beneath the aircraft relative to the ellipsoid to be calculated. This ellipsoidal terrain height is corrected for the variation between the ellipsoid and the geoid (the n-value correction) to produce terrain heights relative to sea level.

Benfield and Geoscience Australia intend to collaborate to improve their respective understanding of risks from natural hazards in Australia. The aim of this project is to exchange ideas, data and models in order to support the respective groups risk modeling expertise.

This is a collection of aerial photography captured from 5 November 2010 to 29 March 2012 and coinciding with a low-water tide occurrence for the purpose of defining the low-water coastline of Tasmania.

This collection contains all national level bathymetry grids held by Geoscience Australia (GA) dating back to survey data obtained since 1993. <b>Value: </b>Bathymetry data is used for a wide range of marine applications including: navigation, environmental assessment, jurisdictional boundaries, resource exploration. <b>Scope: </b>Data holdings lying within the offshore area of Australia, including international waters. <b>To access the AusSeaBed Marine Data Portal</b> use the following link: <a href="https://portal.ga.gov.au/persona/marine#/">https://portal.ga.gov.au/persona/marine#/</a>

Time series seismograph data recorded from Australian National Seismograph Network (ANSN) observatories in Australia, islands in the Pacific, Southern and Indian Ocean's and the Australian Antarctic Territory. <b>Value: </b>This data is used for earthquake monitoring, measurement, detection and location of earthquakes, which is valuable for emergency response, hazard modelling and mitigation. The dataset is also used to meet a subset of Australia's obligations to the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) to fulfil Australia's commitment to nuclear explosion monitoring. <b>Scope: </b>Observatories in Australia, islands in the Pacific, Southern and Indian Ocean's and the Australian Antarctic Territory

This collection includes Global Navigation Satellite System (GNSS) observations from long-term continuous or semi continuous reference stations at multiple locations across Australia and its external territories, including the Australian Antarctic Territory. <b>Value:</b> The datasets within this collection are provided on an openly accessible basis to support a myriad of scientific and societal positioning applications in Australia. These include the development and maintenance of the Australian Geospatial Reference System (AGRS); the densification of the International Terrestrial Reference Frame (ITRF); crustal deformation studies; atmospheric studies; and the delivery of precise positioning services to Australian businesses. <b>Scope: </b> Data from reference stations across Australia and its external territories, including the Australian Antarctica Territory. <b>Access: </b> To access the datasets and query station information visit the <a href="https://gnss.ga.gov.au./">Global Navigation Satellite System Data Centre</a>