Data

Total Magnetic Intensity (TMI) greyscale Image of Australia 2019

Geoscience Australia
Poudjom Djomani, Y.
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=info:doi10.26186/5dd48868ec81b&rft.title=Total Magnetic Intensity (TMI) greyscale Image of Australia 2019&rft.identifier=10.26186/5dd48868ec81b&rft.publisher=Geoscience Australia&rft.description=This image is a greyscale image of the Total Magnetic Intensity of Australia. Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic filed 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 image is created from the 2019 TMI grid with a grid cell size of ~3 seconds of arc (approximately 80 m). This image only includes airborne-derived TMI data for onshore and near-offshore continental areas. The image shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The image can also be used to locate structural features such as dykes.Maintenance and Update Frequency: notPlannedStatement: The 2019 magnetic grid of the Australian region is the seventh edition with a cell size of ~3 seconds of arc (approximately 80 m). This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. 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. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid, about 2 000 000 line-kilometres more than for the previous edition. The 2019 magnetic grid was derived from a complete 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) (Milligan et al., 2009), which serves as a baseline to constrain long wavelengths in the final grid. The levelling and grid-merging procedure was described in detail in Minty et al. (2003). The new 2019 map compilation is comprised of a merge of 1059 survey grids. The addition of almost a decade’s worth of new high-quality surveys adds significantly to the 2010 and 2015 versions of the map. References Milligan, P.R., Minty, B.R.S., Richardson, M. and Franklin, R., 2009. The Australia-wide Airborne Geophysical Survey accurate continental magnetic coverage. Preview, No. 138, p. 1-128. Minty, B.R.S., Milligan, P.R., Luyendyk, A.P.J. and Mackey, T., 2003. Merging airborne magnetic surveys into continental-scale compilations. Geophysics, 68 (3), 988-995.&rft.creator=Poudjom Djomani, Y. &rft.date=2019&rft.coverage=westlimit=112.503782; southlimit=-43.922731; eastlimit=154.662932; northlimit=-9.026912; projection=GDA94 (EPSG:4283)&rft.coverage=westlimit=112.503782; southlimit=-43.922731; eastlimit=154.662932; northlimit=-9.026912; projection=GDA94 (EPSG:4283)&rft_rights=Creative Commons Attribution 4.0 International Licence http://creativecommons.org/licenses/&rft_rights=Australian Government Security ClassificationSystem https://www.protectivesecurity.gov.au/Pages/default.aspx&rft_subject=geoscientificInformation&rft_subject=TMI&rft_subject=magnetics&rft_subject=image&rft_subject=NCI&rft_subject=AU&rft_subject=Magnetism and Palaeomagnetism&rft_subject=EARTH SCIENCES&rft_subject=GEOPHYSICS&rft_subject=Geophysical National Coverage&rft_subject=Airborne Digital Data&rft_subject=Total magnetic intensity&rft_subject=Published_External&rft_subject=magmap&rft_subject=GADDS2.0&rft_subject=2019&rft.type=dataset&rft.language=English Access the data
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Australian Government Security ClassificationSystem
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This image is a greyscale image of the Total Magnetic Intensity of Australia. Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic filed 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 image is created from the 2019 TMI grid with a grid cell size of ~3 seconds of arc (approximately 80 m). This image only includes airborne-derived TMI data for onshore and near-offshore continental areas. The image shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The image can also be used to locate structural features such as dykes.

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Maintenance and Update Frequency: notPlanned
Statement: The 2019 magnetic grid of the Australian region is the seventh edition with a cell size of ~3 seconds of arc (approximately 80 m). This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. 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. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid, about 2 000 000 line-kilometres more than for the previous edition. The 2019 magnetic grid was derived from a complete 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) (Milligan et al., 2009), which serves as a baseline to constrain long wavelengths in the final grid. The levelling and grid-merging procedure was described in detail in Minty et al. (2003). The new 2019 map compilation is comprised of a merge of 1059 survey grids. The addition of almost a decade’s worth of new high-quality surveys adds significantly to the 2010 and 2015 versions of the map. References Milligan, P.R., Minty, B.R.S., Richardson, M. and Franklin, R., 2009. The Australia-wide Airborne Geophysical Survey accurate continental magnetic coverage. Preview, No. 138, p. 1-128. Minty, B.R.S., Milligan, P.R., Luyendyk, A.P.J. and Mackey, T., 2003. Merging airborne magnetic surveys into continental-scale compilations. Geophysics, 68 (3), 988-995.

Created: 04 11 2019

Issued: 20 11 2019

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154.66293,-9.02691 154.66293,-43.92273 112.50378,-43.92273 112.50378,-9.02691 154.66293,-9.02691

133.583357,-26.4748215

text: westlimit=112.503782; southlimit=-43.922731; eastlimit=154.662932; northlimit=-9.026912; projection=GDA94 (EPSG:4283)

Subjects
2019 | AU | Airborne Digital Data | Earth Sciences | GADDS2.0 | Geophysics | Geophysical National Coverage | Magnetism and Palaeomagnetism | NCI | Published_External | TMI | Total magnetic intensity | geoscientificInformation | image | magmap | magnetics |

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Download the data (ers) [6.8 MB]

url : https://d28rz98at9flks.cloudfront.net/131528/131528.zip

National Magnetic And Radiometric Grids WMS

url : http://services.ga.gov.au/gis/geophysical-grids/wms

National Magnetic And Radiometric Grids WCS

url : http://services.ga.gov.au/gis/geophysical-grids/wcs

National Magnetic And Radiometric Grids WMS

local : 140126

National Magnetic And Radiometric Grids WCS

local : 146015

Identifiers
ACN 633 798 857