Airborne Electromagnetics

What is airborne electromagnetics?

Airborne electromagnetics (AEM) is an airborne geophysical technology that was developed for use in the mining industry to locate and map conductive ore bodies. It is a technique that has been applied routinely in Australia in the past five years for mapping salinity and groundwater. It works by measuring variations in the bulk electrical conductivity of the ground.

How does airborne electromagnetics work?

In the Broken Hill Managed Aquifer project, the bulk electrical conductivity of the ground was measured using two helicopters, each carrying a frame suspended beneath the helicopter. The frame houses an electromagnetic transmitter and receiver system. The transmitter sends out electromagnetic signals to the ground. The signals returned to the receiver indicate the electrical conductivity of the ground. Variations in the strength of the induced magnetic field can be interpreted to map groundwater-bearing layers (aquifers), groundwater barriers (aquitards), and groundwater salinity as well as other underground geological features.

Is airborne electromagnetics a safe technology?

AEM is used throughout the world in mineral exploration and in the management of natural resources. In Australia, AEM surveys are flown by specialist contractors who have many decades of experience collecting AEM data in a range of environments. The voltage used in the survey is much less than that carried by household wiring. The altitude of the helicopter (60m) and the frame beneath it (30m) means it is higher than most power lines and the helicopter flies past quickly, which means there is less exposure than that experienced when passing under power lines.

How does airborne electromagnetics affect livestock and horses?

The technology causes no ill effects to livestock and horses, but because low flying helicopters are involved, there is the potential for livestock to be alarmed, including during horse riding activity. To minimise the likelihood of disturbance to livestock, landholders and riders are asked to contact Geoscience Australia via the telephone hot line provided (1800 091 964), and advise of any special situation or circumstance that may require careful scheduling of any planned AEM data collection.

Contact details for specific enquiries

Technical enquires for Broken Hill Managed Aquifer Recharge Project:
Dr Ken Lawrie
Project Leader - Groundwater Group, Geoscience Australia
Tel: +61 2 6249 9847
Email: Ken.Lawrie@ga.gov.au