[oori]

"sealing off caves" - would love to see, or hear the facts. Specifically, about safety of the pressure "chamber".

[newman8r]

https://caes.pnnl.gov/ - it's an interesting project. Apparently it's more like 'underground caverns' than caves.

[jandrese]

I think it is more typically done with old mines. Natural caves are far more complex systems and there are environmental concerns.

[newman8r]

you're right - it looks like the caverns being used for experimentation are the result of solution mining for salt.