Accepted Answer

Infrared imaging detects, as you probably are already aware, temperature differentials.

A truly old grave will have had decades, if not centuries, to achieve thermal equilibrium with the surrounding terrain. Thus it will be exactly the same temperature as the earth around it under most conditions.

But if you used a different detection device, one that used, for example, radio waves to determine in-ground densities, there is an excellent change that the density of an old grave will be less than the density of the surround terrain, even if there are no hollows associated with the old grave, such as you would find with a coffin or other material surrounding the interment site.

And, naturally, if there IS a coffin, the relatively hollow space, even after decades, within the coffin, would register a substantially different density than the surrounding terrain.

Search for density differentials, not temperature differentials, if you are searching for old graves.

Expert:	The Geezer
Pos. Feedback:	100.0 %
Accepts:	88
Answered:	10/15/2009

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