Is there anyway I can determine the depth of soil I have to remove in order to uncover a cave via a sinkhole?

Question

I know this may seem a little weird but there are a few sinkholes that are around in a neighbors yard and I was wondering if I could use sonar or something to figure out the depth of the soil at the"vertex" of the sinkhole and the ceiling of a cave/cavern. If you have any ideas of what I could use give me the approx. cost and where I can get one please. Thanks a lot for your assistance.

Answer 1

There are two ways -- ground penetrating radar, and explosive echo (a sonar-like device that uses small explosions).

Both of these are used by geology crews, mining survey crews, and  military groups.

The approximate cost -- IF you can buy one, is several hundred thousand dollars.

You best bet it to contact the local geological survey group (part of USGS - United States Geological Survey), a local mining company (if you have one in your area), and ask to rent their time and expertise.

The military is VERY unlikely to offer any help, but you might try asking if they have any declassified satellite informatiin.

Answer 2

There are a number of geophysical methods that would allow you to see what you want to see.  How deep is the cave though?  Depending on how deep you think it is, you might be able to see it with shallow seismic reflection surveys, or DC resistivity.  Is the cave filled with fluid, or is it a void space?  If it's hollow then you could use microgravity to find it.  Ground penetrating radar is used in this context a lot as well.

These would not run you hundreds of thousands of dollars.  If you have a local university around, see if they have a geophysics department.  I bet there are some students who would be willing to volunteer their time to come out and do the survey for you.