The magnetic method measures the magnetic field associated with magnetic minerals in rocks. We can map the distribution of magnetic rocks through the variations in the magnetic fields. In Western Australia, the State and Federal governments have collected a lot of regional airborne magnetic data. Airborne magnetic surveys are usually carried out together with radiometric measurements.
The data comes in two main formats:
- Point-located (vector) datasets, which are specific data points in industry-standard formats.
- Raster grids and georeferenced images, which are visual representations of the data.
The Geological Survey of Western Australia (GSWA) also combines data from both government and non-confidential company surveys to create statewide grids and images. The compilation products are updated when new survey data becomes available.
How to access regional airborne magnetic surveys
You can download all geophysical datasets online from MAGIX or place an order to receive larger grids and images on an external drive through the online order form (fees apply). You can search for specific geophysical surveys via a map interface through GeoVIEW.WA.
For national datasets, please go to National Geophysical Archive Data Delivery System (GADDS).
Magnetic anomaly grids of Western Australia
GSWA has created statewide magnetic anomaly grids with cell sizes of 80, 40, and 20 meters. These grids combine data from Federal and State Government surveys and open-file company surveys. Most of this data was collected with line spacing of 500 meters or less. Where closer data isn't available, GSWA uses the Geoscience Australia magnetic grid as a base to fill in gaps.
You can download the latest grid data files in ER Mapper format from MAGIX Online.
Recommended citation
If you use these grids, the suggested reference format is: Brett, JW <year>, <20|40|80> m magnetic (TMI|RTP|1VD) merged grid of Western Australia. Geological Survey of Western Australia.
Available products
Not all products are available for every grid size, but the options include:
- Image files in JP2 and KMZ formats
- Total Magnetic Intensity (TMI) grid
- Reduced to Pole (RTP) of TMI grid (for 80m and 40m)
- First Vertical Derivative (1VD) of TMI grid (for 80m and 40m)
- Multi-scale edges (also called "worms") in vector format (for 80m)
- Metadata sheets with more details about each grid and image
Western Australia 1:250 000 map sheets geophysical images
Magnetic Anomaly Images — showing Total Magnetic Intensity, Total Magnetic Intensity Reduced to Pole, and First Vertical Derivative of Magnetic Intensity — have been created for each 1:250,000-scale map sheet of Western Australia. The data for these images come from the State compilation magnetic grids and have been adjusted to match the data range of each map sheet. You can check the metadata for information on when the data was collected.
You can download the datasets online from MAGIX
Goldfields area, Western Australia — 20 metre grid compilations
Release Date: 12 September 2014
This dataset includes magnetic and radiometric grids covering the Goldfields area of Western Australia, specifically between 120E to 123E longitude and 29S to 33S latitude.
Grid details
- Grid Cell Size: 0.000208 degrees, which is about 20 metres.
Data sources
The compilation includes data from several GSWA regional airborne surveys with 100 metre line spacing:
- Menzies North 2013
- Menzies South 2013
- Kalgoorlie East 2013
- Kurnalpi North 2013
- Kurnalpi South 2014
- Widgiemooltha North 2013
- Widgiemooltha South 2012
It also incorporates data from various open-file company surveys with line spacings of 100 metres or less.
Available downloads
- TMI and Radiometric Grids in ER Mapper format
- Images in JP2 and KMZ formats
How to access the data
- The grids and images from these surveys are available through MAGIX
You can also find the data via the National Geophysical Archive Data Delivery System (GADDS)
