Authors / CoAuthors
Geophysical Acquisition & Processing Section
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. This magnetic grid has a cell size of 0.001 degrees (approximately 110m). The data used to produce this grid was acquired in 1995 by the QLD Government, and consisted of 156230 line-kilometres of data at 400m line spacing and 80m terrain clearance.
Product Type
dataset
eCat Id
105234
Contact for the resource
Owner
Custodian
Point of contact
Digital Object Identifier
Keywords
- ( Theme )
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- TMI
- ( Theme )
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- magnetics
- ( Theme )
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- magnetism and palaeomagnetism
- ( Theme )
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- airborne digital data
- ( Theme )
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- geophysical survey
- ( Project )
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- survey 790
- ( Theme )
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- AWAGS
- ( Data centre )
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- NCI
- ( Discipline )
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- Earth sciences
- ( Discipline )
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- geophysics
- ( Feature type )
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- grid
- ( Place )
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- Australia
- ( Place )
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- QLD
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- Published_External
Publication Date
2011-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Lineage
This mQl0790N.nc grid is an airborne-derived Total Magnetic Intensity (TMI) grid for the Rockhampton 1 & 2, Monto & Munduberra, 1994-1995, Qld, AIRDATA survey. The survey was acquired under the project No. 790 for the geological survey of QLD. The grid has a cell size of 0.001 degrees (approximately 110m). A total of 156230 line-kilometres of data at a line spacing of 400m were acquired to produce this grid. To constrain long wavelengths in the grid, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey grid (Milligan et al., 2009). This survey grid is essentially levelled to AWAGS. 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/. 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 2016-08-29T10:51:42, 2013-05-03T00:00:00 and has its y-axis indexed Southward-positive. References Milligan, P.R., Minty, B.R.S., Richardson, M. & Franklin, R., 2009. The Australia-wide Airborne Geophysical Survey accurate continental magnetic coverage. Preview, No. 138, p. 1-128. Percival, P.J., 2014. Index of airborne geophysical surveys (Fourteenth Edition).
Parent Information
Geophysical Data Collection - Airborne Geophysics
UUID - ddeb0fc4-32e3-4913-80f2-f4249b17a925,
eCat ID - 111301
Extents
[-25.004500, -22.738500, 149.728500, 152.139500]
Reference System
WGS 84 (geocentric) (EPSG:4328)
Spatial Resolution
Service Information
Associations
Downloads and Links
Digital Object Identifier for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
NetCDF file on NCI filesystem for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
THREDDS catalog page for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
NCSS for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
NetCDF file download via HTTP for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
Zipped ERS file download via HTTP for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
OPeNDAP service for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
WCS for dataset 0ea69db1-20e4-48a2-a52d-e41e618c2660
Source Information
This mQl0790N.nc grid includes airborne-derived TMI data for the Rockhampton 1 & 2, Monto & Munduberra, 1994-1995, Qld, AIRDATA survey acquired for the geological survey of QLD