Resistivity – a method for finding anomalies

Published 2010-04-06 00:00:00 | Updated 2010-02-22 11:08:09

Resistivity is a method based on transmitting a known current into the ground and receiving the associated tension response. The result can then be used for finding anomalies compared to the undisturbed soil or rock.

ABEM Instrument AB was once founded for the exploration of minerals in the hunt for more ore bodies to exploit. Many, still operational, mines have been located using the Resistivity method. Today the same geophysical method is used for the tracing of the aftermath of the mining. Resistivity is also well suited for many Civil Engineering investigations, as finding sand and gravel or dept to solid ground.

Where does the contamination go?

Environment is receiving a varied cocktail of matters at waste sites, which is receiving more and more attention. Operators of waste sites are under greater pressure to know what is happening with the near surroundings. Does the waste site have negative effects to environment?

The deposited material changes the electrical properties when leaking into the ground. ABEM Terrameter LS is a tool for monitoring of these conditions, which can act both as an insulator or a conductor. It may also change the properties over time. With a monitoring grid in place, the changes over time can easily be traced through time series of measurements for later follow up surveys or remedies.

Mine tailings

Not all exploration of minerals results in mines. However, whenever it happens it is vital that a close monitoring of what is brought out of the ground is managed in a controllable way. Leachate from mine residue or tailings may become an environmental problem to the surroundings if not harnessed.  Mine operators of today are requested to show that they stay on top of what they do.

Resistivity and especially resistivity monitoring is a powerful tool for this application. ABEM Terrameter LS is helping the owners of such installations to keep control of what is happening. Terrameter LS is installed at site and controlled as well as reporting remotely. A threshold can be set to trigger an alarm, if something beyond expected level is occurring. Thanks to this an eventual contaminant spill can be located and stopped at shortest possible time delay.

Industrial sites

With the accelerating need of grounds to be exploited in the urban areas, a lot of old industrial sites are converted to residential areas. The earlier activities may have led to unwanted remains in the ground, when the development starts these are brought into broad daylight. Geophysics lets the developer know what is hiding in the ground before the digging starts.

The residue material may be of a short lived nature; that is, “self destructing” relatively fast. However, it may be of a more long lived nature, which calls for long term monitoring

The remediation of old industrial sites may call for the need of long term monitoring of the conditions at the site. ABEM Terrameter LS can be installed with a system of contact points in the ground, without disturbing the future access and usage. Remote control lets you make time series measurements for the surveillance.

ABEM Terrameter LS Imaging is used to collect data for further analysis. Thanks to a wider knowledgebase a lot of resource, time and money can be saved.

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