Regional geophysical survey data

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Latest geophysics program update

Data from regional airborne magnetic, radiometric and electromagnetic surveys, ground gravity surveys and deep seismic and magnetotelluric surveys in Western Australia, which are funded by the State or Federal governments, are available from the locations listed below.

Survey source data are provided in the form of point-located (vector) datasets in industry-standard formats. Raster grids and georeferenced images are also available for most surveys.

GSWA also produces statewide compilation grids and images of magnetic, radiometric and gravity data from merged government and non-confidential company surveys (see Airborne Geophysics Index). Compilation products are updated as new survey datasets become available.

Online data downloads are free of charge.

Media and handling charges apply for datasets requested on physical media via:

Survey source datasets

Statewide geophysical compilations

State compilation grids and images may be downloaded at no charge via the links below or from the GSWA Projects directory in the Pawsey Supercomputing Centre public data store.

These grids are not available to download from GADDS.

Magnetic anomaly grids of Western Australia

Magnetic anomaly grid compilations at 80, 40 and 20 metres in cell size are generated by merging grids from Federal and State Government datasets, acquired with a line spacing of 500 metres or less and more than 1300 openfile company datasets at various line spacing.

The 'Geoscience Australia magnetic grid of Australia V6 2015' has been used as a base  reference grid and is also used to complete the background areas where closer spaced data is not available.

Pseudocolour images in JP2 format for each compilation grid were generated with a colour palette of red high and blue low using histogram equalisation. To emphasise the expression of high-frequency anomalies, an artificial illumination was applied from the northeast.

The grid data files in ER Mapper format may be downloaded via the links below or from the Pawsey Centre public data store.

Magnetic anomaly grids (80 m) of Western Australia (2016 – version 1)

Date released: 6 May 2016

These grids have a cell size of approximately 80 metres (0.000833333 degrees). Each grid file is approximately two gigabytes.

Magnetic anomaly grids (40 m) of Western Australia (2016 – version 1)

Date released: 6 May 2016

Compared with the 80 metre grid, the 40 metre grid will contain improved detail in areas of survey line spacing of 300 metres or less — the shaded areas alongside. In other areas there will be no difference in frequency content from  the 80 metre grid; however, image pixelation will be less apparent at larger viewing scales.

These grids have a cell size of approximately 40 metres (0.00041666 degrees). Each grid file is approximately eight gigabytes.

Magnetic anomaly grid (20 m) of Western Australia (2016 – version 1)

Date released: 19 October 2016

The grid has a cell size of approximately 20 metres (0.00020823 degrees). The grid file is approximately 30 gigabytes. It is available only from the Pawsey Centre public data store.

 

Radiometric grids (80 m) of Western Australia (2016 – version 1)

Date released: 22 July 2016

These four grid compilations at 80 metre cell size combine merged total count, potassium, uranium and thorium data (converted to radioelement concentrations) for onshore Western Australia. They are generated from Federal and State Government datasets, acquired with a line spacing of 500 metres or less and more than 100 open-file company datasets at various line spacings. The 'Geoscience Australia radiometric map of Australia (radmap10)' has been used to provide the base reference grids.

The grids have a cell size of approximately 80 metres (0.000833333 degrees). Each grid file is approximately two gigabytes in size.

Pseudocolour images in JP2 format have been compiled for download at no charge. For the ternary radiometric image, potassium, thorium and uranium elements are displayed as red, green and blue.

The grid data files in ER Mapper format may be ordered via the links below or from the Pawsey Centre public data store.

Gravity anomaly grid (400 m) of Western Australia (2017 — version 1)

Date released: 23 February 2017

The grid has a cell size of approximately 400 metres (0.00416666 degrees). A pseudocolour image in JP2 format has been generated from a colour palette (red high. blue low) using a linear histogram. To emphasise the expression of high-frequency anomalies, an artificial illumination was applied from overhead.

Satellite ASTER geoscience map of Western Australia

Satellite ASTER
Satellite ASTER

Date released: 15 November 2011

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) geoscience map of Western Australia is a set of public, digital geoscience products generated from satellite ASTER data. The project was a collaboration between the Department of Mines and Petroleum and the Centre for Three Dimensional Mineral Mapping Centre of Excellence (C3DMM) led by the CSIRO Minerals Down Under Flagship.

There are 17 ‘mineral group’ composition maps in the set, including 14 from ASTER’s nine visible, near-infrared (VNIR) and shortwave infrared (SWIR) ‘reflected’ bands, and three from ASTER’s five thermal infrared (TIR) bands. The products are available as geographic information system (GIS) compatible images (e.g. TIF and JPG format) or in image-processing software format (e.g. BSQ with headers). The State ASTER maps have been carved into 1:1 000 000 map sheet blocks with individual file sizes reduced to ~100 megabytes each.

Western Australia 1:250 000 map sheets geophysical images

Date released: 3 October 2016

The following geophysical images in JP2 format have been generated for individual 1:250 000-scale map sheets of Western Australia. The data for each sheet were extracted from the current State compilation grids and were histogram-stretched to match the data range in each sheet.

  1. Bouguer Gravity images — colour
  2. Radiometric images of Potassium, Thorium, Uranium, Total Count - colour
  3. Ternary radiometric images of Potassium, Thorium, Uranium (KTU) — Red Green Blue composite
  4. Magnetic anomaly images
    • Total magnetic intensity — colour
    • Total magnetic intensity reduced to pole — colour
    • First vertical derivative of total magnetic intensity reduced to pole — colour
    • First vertical derivative of total magnetic intensity reduced to pole — grey scale

Goldfields area, Western Australia — 20 metre grid compilations

Goldfields area, Western Australia — 20 m grid compilations
Goldfields area, Western Australia — 20 m grid compilations

Date released: 12 September 2014

Compilation magnetic and radiometric grids and images covering the Goldfields area of Western Australia bounded by meridians 120E to 123E and parallels 29S to 33S.

The grid cell size is 0.000208 degrees (approximately 20 m).

The compilations include data from the following regional GSWA airborne surveys at 100 m line spacing: R70824 Menzies North 2013, R70824 Menzies South 2013, R70824 Kalgoorlie East 2013, R70824 Kurnalpi North 2013, R70824 Kurnalpi South 2014, R70824 Widgiemooltha North 2013 and R70824 Widgiemooltha South 2012.

Data from a number of open-file company surveys at line spacings of 100 m or less have also been included in the compilations.

Grids and images from the individual regional surveys are available via the GeoVIEW.WA application; located data from the National Geophysical Archive Data Delivery System (GADDS).

GGMplus gravity acceleration data compilation over Western Australia

Date released: 11 October 2013

GGMplus (Global Gravity Model +) is a composite of GRACE and GOCE satellite gravity, EGM2008 and short-wavelength topographic gravity effects at 200 m resolution for all terrestrial and near-coastal areas of the Earth between ±60° latitude. For details see:

Hirt, C., S.J. Claessens, T. Fecher, M. Kuhn, R. Pail, M. Rexer (2013) New ultrahigh-resolution picture of Earth's gravity field, Geophysical Research Letters, Vol 40, doi: 10.1002/grl.50838

The paper and the data are available for download from the GGMplus website.

The GGMplus source data are distributed as a series of 5° x 5° tiles at a grid resolution of 0.002 degrees (7.2 arc-seconds). Geological Survey of Western Australia (GSWA) has compiled the ‘free fall gravity acceleration’ data from the 18 tiles that cover Western Australia into a single grid for the area bounded by parallels 12S–36S and meridians 112E–130E. By agreement with the authors, the compilation grid is made available here for download in ER Mapper and Geosoft grid formats. The gravity acceleration data are in units of µms-2 (gravity units).

Important: Short-wavelength features less than about 10 km in the GGMplus data are not derived from observations but were computed from 7.5 arc-second (~200 m) SRTM topography by assuming a constant density of 2 670 kgm-3 .

These short-wavelength features are NOT amenable to standard ‘mass difference’ interpretations. 

Contact
For more information contact:
geophysics@dmp.wa.gov.au