Authors / CoAuthors
Abstract
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 GA310 South West Margin 2D MSS were acquired for Geoscience Australia in 2008/2009 as part of the Australian Government's Offshore Energy Security Program. 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. A total of 26,000 line-kilometres of magnetic and gravity data were acquired during this survey.
Product Type
dataset
eCat Id
140143
Contact for the resource
Resource provider
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Keywords
- theme.ANZRC Fields of Research.rdf
-
- GEOPHYSICSMagnetism and PalaeomagnetismEARTH SCIENCES
- ( Theme )
-
- magnetic
- ( Feature type )
-
- line
- ( Feature type )
-
- vector
- ( Platform )
-
- shipborne
- ( Platform )
-
- marine
- ( Project )
-
- GA310
- ( Place )
-
- South West Margin
- ( Place )
-
- SW margin
-
- Published_External
Publication Date
2020-07-14T05:30:44
Creation Date
Security Constraints
Legal Constraints
Status
required
Purpose
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
This data is a shipborne-derived magnetic line dataset for the GA310 South West Margin 2D MSS seismic survey. The data was acquired for Geoscience Australia in 2008/2009 under the project No. GA310 as part of the Australian Government's Offshore Energy Security Program. A total of 26,000 line-kilometres of gravity and magnetic data were acquired during this seismic survey. 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/.\n\nReferences:\nIntrepid Geophysics, http://www.intrepid-geophysics.com .\nPercival, P.J., 2014. Index of airborne geophysical surveys (Fourteenth Edition).
Parent Information
Extents
[-36.90, -19.00, 105.00, 117.90]
Reference System
Spatial Resolution
Service Information
Associations
Source Information