There’s a old riddle that asks ‘What gets bigger by taking more away from it?’ Ans: The hole. Seems like it also gets more interesting. This article speaks of the world’s deepest man made hole.
https://www.treehugger.com/the-world...al-cap-4863210
Temperatures prevented further drilling but along the way they made discoveries, some new and some dispelling of old truths, as well as exposing how little we know of what’s below us.
You don’t hear much about capturing geothermal energy. There’s plenty of warmth down there, just need to transfer it topside. Too bad we couldn’t drill a 12km hole beneath every edifice, control and enable heat. Suspect costs of drilling are exorbitant but new techniques do come along. There may be an environmental impact but no idea what that might be.