Full description
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 Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) is the first vertical derivative of the complete spherical cap Bouguer anomaly grid for the Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur Barkley, Northern Territory, 2019. This gravity survey was acquired under the project No. 201901 for the geological survey of NT, QLD. The grid has a cell size of 0.00461 degrees (approximately 500m). A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid. A total of 5855 gravity stations at a spacing between 2000m and 4000m were acquired to produce this grid.
Lineage
Maintenance and Update Frequency: notPlanned
Statement: This Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) is the first vertical derivative of the complete spherical cap Bouguer anomaly grid for the Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur Barkley, Northern Territory, 2019. This gravity survey was acquired under the project No. 201901 for the geological survey of NT, QLD. The grid has a cell size of 0.00461 degrees (approximately 500m). A total of 5855 gravity stations at a spacing between 2000m and 4000m were acquired to produce this grid. Three processes are required to correct the gravity observations for the effects of the surrounding topography: (1) a Bouguer correction (Bullard A), which approximates the topography as an infinite horizontal slab; (2) a correction to that horizontal slab for the curvature of the Earth (Bullard B); and (3) a terrain correction (Bullard C), which accounts for the undulations of the surrounding topography. The complete spherical cap Bouguer gravity anomalies were calculated by applying terrain correction (Bullard C) to the spherical cap Bouguer anomaly point data of Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur Barkley, Northern Territory, 2019. These terrain corrections were calculated using software from INTREPID Geophysics. The Intrepid algorithm utilises concentric rings subdivided into cells (Direen, 2001) to calculate the terrain correction. The terrain corrected data were then gridded using a gridding technique provided by the INTREPID Geophysics software package. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the Bouguer gravity grid of the Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur Barkley, Northern Territory, 2019 survey to produce this grid. This grid was calculated using an algorithm from the INTREPID Geophysics software package. The processed data are checked by GA geophysicists using standard methods for assessing quality to ensure that the final data are fit-for-purpose. Details of the specifications of individual surveys held in the Australian National Gravity Database (ANGD) can be found in the Second Edition of the Index of Gravity Surveys (Wynne and Bacchin, 2009).
References:
Intrepid Geophysics, http://www.intrepid-geophysics.com;
Wynne, P. and Bacchin, M., 2009. Index of Gravity Surveys (Second Edition). Geoscience Australia, Record 2009/07.
Created: 31 10 2020
Issued: 31 10 2020
Modified: 05 07 2021
Data time period: 03 07 2019 to 21 08 2019
text: westlimit=133.9808; southlimit=-18.2617; eastlimit=135.3869; northlimit=-16.8094; projection=GDA94 (EPSG:4283)
Subjects
1VD |
Australia |
Bouguer |
EARTH SCIENCES |
Earth sciences |
GADDS2.0 |
NCI |
NT |
Published_External |
QLD |
complete |
first vertical derivative |
geophysical survey |
geophysics |
geoscientificInformation |
grav |
gravity |
grid |
ground digital data |
raster |
spherical cap |
survey 201901 |
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Other Information
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. (File available for download in various formats from the GADDS2 portal)
url :
https://portal.ga.gov.au/persona/gadds
File download for Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) (Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) file download)
NetCDF Subsetting Service (NCSS) for Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) (Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) NCSS)
OPeNDAP web service for Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) (Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) OPeNDAP)
OGC Web Mapping Service (WMS) for Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) (Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) WMS)
OGC Web Coverage Service (WCS) for Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) (Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) WCS)
Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) NCSS
Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) OPeNDAP
Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) WMS
Tennant Creek-Mt Isa (TISA) Gravity Surveys, South West McArthur (CSCBA 1VD grid) WCS
Identifiers
- URL : pid.geoscience.gov.au/dataset/ga/144805
- global : 862daa16-5d2c-430c-bf18-31347e064484
