How to detect discontinuous permafrost

[georam]

Is there a state of the art technique on how to detect the presence of ice, ice chunks, ice lenses which grow under the ground , particularly in the discontinuous permafrost region ?<br>
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I am looking for technique or equipment which can "sweep" the ground and provide reliable results of "x-ray" view of the ground with locations of ice lenses, thickness and depths. Is GPR (ground penetrating radar) , or electrical resistivity can map this ? Will air photo using infra red film can detect this ?<br>
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Thanks

 

[GlacierEng]

Yes, ground penetrating radar (GPR) and resistivity can map permafrost, but so can other surface electromagnetic (EM) methods. GPR and surface EM are more rapid methods than surface resistivity, and thus, are usually less costly to implement. However, the key questions to answer before using any method are:<br>
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1. What is the host soil material? If it has a high concentration of clay, GPR may not be of use because of the attentuation of radar signals in clay soils. Likewise, if there is not a significant contrast in electrical properties between the ice and surrounding soil, then electrical/EM methods may not be your best choice.<br>
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2. What is the approximate depth and extent of the permafrost your trying to identify? This will aid in designing the survey.<br>
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3. How accessible is the surface? Are there any surface features or cultural 'noise' sources that may interfere with the measurements and that may inhibit detection/imaging of the permafrost layers? <br>
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Aerial methods to image permafrost may work, but will only be able to identify large-scale changes in their extent. <br>
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Hope this helps.<br>
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Alan