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Magnetic Anomaly Map of Australia, Seventh Edition, 2020 - Enhanced Products Package - TMI RTP AS image

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Created 20/01/2025

Updated 20/01/2025

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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 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 AS image is a analytic signal of the Total Magnetic Intensity grid for the Magnetic Anomaly Map of Australia, Seventh Edition, 2019. 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 data, about 2 000 000 line-kilometres more than for the previous edition. The grid used to produce this image has a cell size of 0.00083 degrees (approximately 80m). The grid has units of nanoTesla per km (or nT/km). The VRTP processing followed a differential reduction to pole calculation up to 5th order polynomial. Magnetic inclination and declination were derived from the IGRF-15 geomagnetic reference model using a data representative date and elevation representative of the survey. An analytic signal was calculated by applying a fast Fourier transform (FFT) process to the Total Magnetic Intensity grid of the Magnetic Anomaly Map of Australia, Seventh Edition, 2019 to produce the grid represented in this image. The Analytic Signal is the square root of the sum of the two horizontal derivative and the vertical derivative.

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Field Value
Title Magnetic Anomaly Map of Australia, Seventh Edition, 2020 - Enhanced Products Package - TMI RTP AS image
Language eng
Licence notspecified
Landing Page https://devweb.dga.links.com.au/data/dataset/3e2ef3c2-339d-4644-8ebd-82e1d9316ade
Contact Point
Geoscience Australia
clientservices@ga.gov.au
Reference Period 01/01/2019 - 31/12/2019
Geospatial Coverage {"type": "Polygon", "coordinates": [[[105.9996, -43.9301], [154.6635, -43.9301], [154.6635, -9.0265], [105.9996, -9.0265], [105.9996, -43.9301]]]}
Data Portal data.gov.au

Data Source

This dataset was originally found on data.gov.au "Magnetic Anomaly Map of Australia, Seventh Edition, 2020 - Enhanced Products Package - TMI RTP AS image". Please visit the source to access the original metadata of the dataset:
https://devweb.dga.links.com.au/data/dataset/magnetic-anomaly-map-of-australia-seventh-edition-2020-enhanced-products-package-tmi-rtp-as-ima

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