The Geophysical Data Collection hosted at the National Computational Infrastructure (NCI) contains individual airborne survey lines of geophysical data, including Total Magnetic Intensity, Gamma-ray spectrometry (radiometrics - K, Th, U) and elevation, as well as, ground based Bouguer Gravity. These datasets have been used to create both survey scale and national grids for the geophysical data types. The data were sourced from publicly available government- and company-acquired geophysical surveys in Australia and its surrounding marine area. Other GA Geophysical Data Collections not held at the NCI are discoverable via <a href="https://pid.geoscience.gov.au/dataset/ga/100444">eCat# 100444</a>

Digital elevation models (DEMs) reflect the morphology of landscape surfaces and attributes derived from these models, including slope, aspect, relief and topographic wetness index. DEMs have broad application in geomorphology, geology, hydrology, ecology and climatology. Here, we consider two important terrain attributes: topographic position index and topographic ruggedness. Topographic position index measures the topographic slope position of landforms. It compares 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 DEM to derive the relative topographic position (e.g. upper, middle, lower landscape elements). Ruggedness refers to the roughness of the surface and is calculated as the standard deviation of elevations. Both these terrain attributes are scale dependent and will vary according to the size of the analysis window. Here, we generated a multiscale topographic position model over the Australian continent using a 3-second resolution (~90 m) DEM derived from the Shuttle Radar Topography Mission. The algorithm calculates topographic position scaled by the corresponding ruggedness across three spatial scales (window sizes): 0.2–8.1 km, 8.2–65.2 km and 65.6–147.6 km. The derived ternary image captures variations in topographic position across these spatial scales, giving a rich representation of nested landform features, with broad application to understanding geomorphological and hydrological processes, and mapping regolith and soils. <b>Citation:</b> Wilford, J., Basak, S. and Lindsay, J., 2020. Multiscale topographic position image of the Australian continent. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

<div>The Canobie Airborne Gravity Gradiometer (AGG) survey of Northern Queensland was flown between 24 November and 3 December 2021. </div><div>Contracted to Xcalibur Multiphysics, Geoscience Australia undertook the project management, contract management and quality control on behalf of the Geological Survey of Queensland. </div><div>The located data, gridded data and quality control reports are contained within this record. </div><div><br></div><div>Survey area was centered on latitude 19° 31’ 04” S and longitude 140° 44’ 14” E to the north of Cloncurry. A total of 8 production flights were flown for a combined total of 4,712.4 </div><div>line kilometers of data and acquired on 1000 m line spacing at 80 m nominal terrain clearance</div><div>Quality control was performed by airborne gravity consultant Dr Mark Dransfield on behalf of Geoscience Australia, with his report included here.</div><div><br></div><div>The survey was designed to supplement the regional legacy ground gravity data and improve the definition of gravimetric anomalies in a region deemed highly prospective for base metals exploration. </div><div>In addition, the AGG survey will provide better understanding of the cover sequence thickness (estimated to be less than 100 m) and characteristics of the underlying basement geology. </div><div><br></div><div>The data was released by the Geological Survey of Queensland on March 29 and can be found at https://geoscience.data.qld.gov.au/dataset/gg100099/resource/geo-spa460972-gg100099. </div><div><br></div><div>Survey Name: Canobie airborne gravity gradiometery survey,2021</div><div>Datasets Acquired: Gravity gradiometry, digital terrain model</div><div>Geoscience Australia Project Number: P5021</div><div>Acquisition Start Date: 24/11/2021</div><div>Acquisition End Date: 03/12/2021</div><div>Flight line spacing: 1000 m</div><div>Flight line direction: East-West (090-270)</div><div>Total distance flown: 4,712 line-km</div><div>Nominal terrain clearance: 80 m</div><div>Blocks: 1</div><div>Data Acquisition: Xcalibur Multiphysics</div><div>Project Management: Geoscience Australia</div><div>Quality Control: Mark Dransfield on behalf of Geoscience Australia</div><div>Dataset Ownership: Geological Survey of Qld and Geoscience Australia</div><div><br></div><div>Included in this release:</div><div>1. Point-located Data</div><div>ASCII-column data with accompanying description and definition files.</div><div>• Gravity gradiometry data including the various corrections</div><div>• Gravity gradiometry data noise estimates</div><div>• Vertical gravity estimate including various reduction and levelled corrections</div><div>• Digital terrain model</div><div><br></div><div>2. Grids</div><div>Gridded data in ERMapper (.ers) format (GDA2020):</div><div>• Gravity gradiometry</div><div>• Free-air corrected vertical gravity</div><div>• Terrain and bouguer corrected vertical gravity</div><div>• Digital terrain model</div><div><br></div><div>3. Reports</div><div>• Contractors Logistics Report</div><div>• Quality Control Report (Mark Dransfield)</div><div><br></div><div>4. Location</div><div>• ARCGIS shape file</div><div><br></div><div><br></div><div>© Geological Survey of Queensland and Commonwealth of Australia (Geoscience Australia) 2021. With the exception of the Commonwealth Coat of Arms and where otherwise noted, this product is provided under a Creative Commons Attribution 4.0</div>