ba99de35-faaf-452b-aa18-f00300a54e1a urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2026-04-04T06:22:06 creation ISO 19115 2016 National Gravity Compilation 2019 DGIR tilt grid ba99de35-faaf-452b-aa18-f00300a54e1a Gravity data measure 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. This National Gravity Compilation 2019 DGIR tilt grid is produced from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid has a cell size of 0.00417 degrees (approximately 435m). The data are derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented by offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with marine data were used to generate this grid. The ground gravity data used in the national grid has 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. Station spacing for ground observations varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. The DGIR was obtained by subtracting 3 quantities (i.e., the near-field isostatic correction, the far-field isostatic correction, and a first order trend correction) from Complete Bouguer Anomaly data (CBA) of the 2019 Australian National Gravity Grids A series. The grid shows a tilt of the de-trended global isostatic residual (DGIR) anomalies (A series) over Australia and its continental margins. A tilt filter was calculated by applying a fast Fourier transform (FFT) process to the DGIR grid of the 2019 Australian National Gravity Grids A series. A tilt filter is a ratio of the vertical derivative to the total horizontal derivative and is used for detection of edges of geological units. {"type": "Polygon", "coordinates": [[[107.9979, -48.0021], [164.0021, -48.0021], [164.0021, -7.9979], [107.9979, -7.9979], [107.9979, -48.0021]]]} 107.9979 164.0021 -48.0021 -7.9979 A series Australia EARTH SCIENCES Earth sciences GADDS2.0 NCI None Published_External de-trended geophysical survey geophysics grav gravity grid ground digital data isostatic marine data national raster residual satellite data survey 202008 tilt File available for download in various formats from the GADDS2 portal documentDigital The Geophysical Archive Data Delivery System (GADDS2) portal provides HTTP download of geophysics datasets in a number of formats. Point and line datasets are available in NetCDF and ASEG-GDF2. Grid datasets are available in NetCDF, GeoTIFF and ERS. HTML National Gravity Compilation 2019 DGIR tilt grid file download documentDigital File download for National Gravity Compilation 2019 DGIR tilt grid application/x-netcdf National Gravity Compilation 2019 DGIR tilt grid NCSS documentDigital NetCDF Subsetting Service (NCSS) for National Gravity Compilation 2019 DGIR tilt grid HTML National Gravity Compilation 2019 DGIR tilt grid OPeNDAP documentDigital OPeNDAP web service for National Gravity Compilation 2019 DGIR tilt grid HTML National Gravity Compilation 2019 DGIR tilt grid WMS documentDigital OGC Web Mapping Service (WMS) for National Gravity Compilation 2019 DGIR tilt grid WMS National Gravity Compilation 2019 DGIR tilt grid WCS documentDigital OGC Web Coverage Service (WCS) for National Gravity Compilation 2019 DGIR tilt grid WCS