national
Type of resources
Keywords
Publication year
Topics
-
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 0.5VD 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 this 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 grid shows the half vertical derivative of the de-trended global isostatic residual anomalies (A series) over Australia and its continental margins. The original 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. A half vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the DGIR grid of the 2019 Australian National Gravity Grids to produce this grid.
-
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 includes airborne DGIR 1VD grid is produced from the 2019 Australian National Gravity Grids B 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. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground and airborne gravity data used in this 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. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. The grid shows the first vertical derivative of the de-trended global isostatic residual (DGIR) anomalies over Australia and its continental margins. The DGIR grid 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 B series. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the DGIR grid of the 2019 Australian National Gravity Grids to produce this grid.
-
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 1VD 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 this 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 grid shows the first vertical derivative of the de-trended global isostatic residual anomalies (A series) over Australia and its continental margins. The original 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. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the DGIR grid of the 2019 Australian National Gravity Grids to produce this grid.
-
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.
-
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 includes airborne DGIR tilt grid is produced from the 2019 Australian National Gravity Grids B 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. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground and airborne gravity data used in this 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. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. The grid shows a tilt of the de-trended global isostatic residual (DGIR) anomalies over Australia and its continental margins. The DGIR grid 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 B series. A tilt filter was calculated by applying a fast Fourier transform (FFT) process to the DGIR grid of the 2019 Australian National Gravity Grids B series to produce this grid. 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.
-
Digital Elevation data record the terrain height variations from the processed point-located data recorded during a geophysical survey. This National Gravity Compilation 2019 ground elevation ellipsoid image (hillshade HSI) is elevation of the observation surface for the gravity data in the 2019 A Series grids relative to the GRS80 ellipsoid (GDA94 datum). These data were acquired under the project No. 202008. The ground surface data were derived from SRTM data with 3 second grid cell size. The grid used to produce this image has a cell size of 0.00417 degrees (approximately 435m). The data are given in units of meters. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose.
-
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 includes airborne CSCBA image is an image derived from the 2019 Australian National Gravity Grids B series. These gravity data were acquired under the project No. 202008. The grid used to produce this image has a cell size of 0.00417 degrees (approximately 435m). The data are given in units of um/s^2, also known as 'gravity units', or gu. This gravity anomaly grid is 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 Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground gravity data used in this 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 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. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. The image shows complete Bouguer anomalies (B series) over Australia and its continental margins. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data.
-
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 CSCBA image is an image derived from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid used to produce this image has a cell size of 0.00417 degrees (approximately 435m). The data are given in units of um/s^2, also known as 'gravity units', or gu. This gravity anomaly grid is 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, and marine data were used to generate this grid. The ground gravity data used in this 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 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. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. The image shows complete Bouguer anomalies (A series) over Australia and its continental margins. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data.
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The 2019 Total magnetic Intensity (TMI) grid of Australia has a grid cell size of ~3 seconds of arc (approximately 80 m). This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. Since the sixth edition was released in 2015, data from 234 new surveys have been added to the database, acquired mainly by the State and Territory Geological Surveys. The new grid was derived from a re-levelling of the national magnetic grid database. The survey grids were levelled to each other, and to the Australia Wide Airborne Geophysical Survey (AWAGS), which serves as a baseline to constrain long wavelengths in the final grid. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid, about 2 000 000 line-kilometres more than for the previous edition. The data 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 Magnetic Anomaly Map of Australia, Seventh Edition, 2020 - Enhanced Products Package - TMI RTP 1VD grid (AWAGS) is a first vertical derivative grid of the TMI RTP grid of the Magnetic Anomaly Map of Australia, Seventh Edition, 2019. This grid has a cell size of 0.00083 degrees (approximately 88m) and given in units of nT per metre (nT/m). This grid shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The grid can also be used to locate structural features such as dykes.
-
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 - CSCBA 0.5VD grid is derived 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). This gravity anomaly grid is 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 Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry 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 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. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The grid shows half derivative of the complete Bouguer anomalies over Australia and its continental margins. A half vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids A series to produce this grid.