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. These line dataset from the GA302 Capel and Faust Basins MSS survey were acquired in 2006 for Geoscience Australia. This survey acquired a range of pre-competitive geological and geophysical data that included seismic reflection, gravity, magnetic and swath bathymetry measurements, as well as seafloor dredge samples.
GEOPHYSICSMagnetism and PalaeomagnetismEARTH SCIENCES
Capel and Faust
Australian Government Security ClassificationSystem
Classification - unclassified
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This data is a shipborne-derived magnetic line dataset for the GA302 Capel and Faust Basins MSS seismic survey. The data was acquired for Geoscience Australia in 2006 under the project No GA302. This survey acquired a range of pre-competitive geological and geophysical data that included seismic reflection, gravity, magnetic and swath bathymetry measurements, as well as seafloor dredge samples.
Levelling is a key step in processing shipborne gravity data. This process minimises the mistie errors at ship-track cross-overs that arise from factors such as positioning errors, instrument drift and lack of diurnal corrections to magnetic data. Without accounting for these cross-over errors, gridded data can be rendered un-interpretable by artefacts and distortions at line cross-overs. The data processing and levelling were conducted using the INTREPID software from Intrepid Geophysics. The processed data was checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. Details of the specifications of individual airborne surveys can be found in the Fourteenth Edition of the Index of Airborne Geophysical Surveys (Percival, 2014). This Index is also available online at http://pid.geoscience.gov.au/dataset/79134. Further up to date information about individual surveys can also be obtained online from the Airborne Surveys Database at http://www.ga.gov.au/oracle/argus/. Reference: \nIntrepid Geophysics, http://www.intrepid-geophysics.com .\nPercival, P.J., 2014. Index of airborne geophysical surveys (Fourteenth Edition).