ChrisJC said:
Has anybody tried looking for caves using Microgravity?
If this is to be believed:
https://www.keele.ac.uk/geophysics/microgravity/typicalsurveys/cavesystem/#tabs-6
then digging could be much better targeted to where there is definitely cave passage!
Chris.
Small world. I spent a few years carrying out gravity, seismic and borehole surveys for NIREX around Windscale/Sellafield in the mid / late '80s.
https://en.wikipedia.org/wiki/Nirex
The gravitational acceleration changes according to the density of the ground. Sensitive gravimeters, used over large areas can plot underground variations in density down thousands of metres.
https://en.wikipedia.org/wiki/Gravimeter
Finding voids (caves/mines) is very easy as the results are very obvious.
Our survey programme consisted of gravi survey, seismic survey and finally boreholes to 1500m and more. The object, although denied at the time but later admitted, was to find suitably dense, sound bodies of rock in which to mine out caverns to form repositories for underground disposal of nuclear waste.
https://www.researchgate.net/publication/249557436_Lithostratigraphy_of_a_concealed_caldera-related_ignimbrite_sequence_within_the_Borrowdale_Volcanic_Group_of_west_Cumbria#pf2
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjqsI6yv4fvAhVTaRUIHXRIATIQFjADegQICxAD&url=https%3A%2F%2Frwm.nda.gov.uk%2Fpublication%2F023-sellafield-geological-and-hydrogeological-investigations-the-geological-structure-of-the-sellafield-site-1997%2F%3Fdownload&usg=AOvVaw0_f8q1Q-N86oMs2AhhmvWh
I was at Parys Mountain in 89/91 sinking the new Morris Shaft; the story at the time being that it was for the same purpose.
You decide.....