First vertical derivative of the Bouguer gravity grid of West Murchison Gravity survey
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Geophysical Acquisition & Processing Section
Gravity data measures 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 West_Murchison_Gravity_CSCBA267GUVD_geodetic.nc grid is a first vertical derivative of the Bouguer anomaly grid for the West Murchison Gravity survey. This gravity survey was acquired under the project No. 201260 for the geological survey of WA. The grid has a cell size of 0.00477693 degrees (approximately 500m). A total of 11816 gravity stations were acquired to produce the original grid. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.
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This West_Murchison_Gravity_CSCBA267GUVD_geodetic.nc grid is a first vertical derivative grid of the Bouguer anomaly for the West Murchison Gravity survey. This gravity survey was acquired under the project No. 201260 for the geological survey of WA. The grid has a cell size of 0.00477693 degrees (approximately 500m). A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the Spherical Cap/complete Spherical cap/Bouguer gravity grid of the West Murchison Gravity 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. The first vertical derivative grid is very helpful for the enhancement of near surface features and structural features such as faults and dykes. 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).
The original grid was converted from ERMapper (.ers) format to netCDF4_classic format using GDAL1.11.1. The main purpose of this conversion is to enable access to the data by relevant open source tools and software. The netCDF grid was created on 2017-10-19T01:52:30, 2012-12-20T00:00:00.
Intrepid Geophysics. http://www.intrepid-geophysics.com. Wynne, P., and Bacchin, M., 2009. Index of Gravity Surveys (Second Edition). Geoscience Australia, Record 2009/07.