Obviously wells and so on were incredibly important to the growth of civilization. I know that in Africa and Arabia people would bore tunnels underneath hills so that they would intersect with the water table and carry the water to an accessible area. These are called foggara or qanats depending on where they are. They were, I believe, crucial to places that were otherwise not arable and barren. It's my understanding that when they find water in the mantle, it's not an ocean in the usual sense of an open body of water because of the heat and the pressure. If that's the case, is there any practical or even theoretical application of drilling that deeply into the Earth? The article seems to suggest that just from knowing that there's water at that depth in that quantity is sufficient to understand its effects.