Superdeep Borehole Mining

[NoXion]

I read the Wiki article on the Kola Superdeep Borehole and it got me thinking - let's say for the sake of argument that drilling to similar (perhaps greater) depths and extracting whatever is found down there, could be achieved as cheaply and as easily (if not more so) as traditional mining techniques. Is there any plausible benefit to doing this? Are there any resources down there, known or potential, that could be worth exploiting?

Additionally, what other benefits could be gained by the ability to easily drill to extreme depths of the Earth's crust? Would it facilitate a revolution in geothermal energy? What if the mantle, or at least the outermost portion of it, was in easy reach?

[Jeremy]

Soviet Our material science and engineering would be greatly advanced if this were an easy task. That should be beneficial.

I do not think that such feats would be worthy of whatever resources they could bring back through such a small diameter shaft.

[Sea Skimmer]

Minerals should exist all throughout the depth of the earths crust. The problem is finding the locations of ores which are profitable to mine. Even on the surface of the earth that can be difficult. Underground you can use seismic surveys to locate different layers of rock, but the only way to figure out what those layers contain mineral wise is going to be drilling. Oil can be found easily because it’s a liquid; making it somewhat obvious. So even if the extraction costs are solved, the costs of starting a mine will still be a holdback.

The number one advantage would be we could remove our current risk of depleting all surface deposits of certain strategic minerals. In terms of improving say the price of iron or accessibility of copper I’m not sure it would change a lot, at least not until we have considerably further depleted deposits close to the surface. That will happen some day but the earth has a lot of spots left to mine as recent discoveries in Afghanistan show.

[Zaune]

Limitless supplies of magma, adamantine and Hidden Fun Stuff?

Sorry, couldn't resist that.

[NoXion]

Limitless supplies of magma, adamantine and Hidden Fun Stuff?

Sorry, couldn't resist that.

Actually, that's an appealing thing about this in science fictional terms. Depending on average how far one can stretch the audience's suspension of disbelief, as well as the conventions of the setting, one could perhaps stash away all sorts of things down there for a near-future civilisation to discover. The idea that there could be immense riches and/or strange (perhaps even eldritch) mysteries hidden under the earth is, to me at least, a powerful one, reminiscent of old tales about the underworld. That such riches and mysteries are discovered and unraveled through means technological and scientific only adds to the appeal by making it more relevant.

[Purple]

So the good old hollow earth idea?

http://en.wikipedia.org/wiki/Hollow_earth

[NoXion]

So the good old hollow earth idea?

http://en.wikipedia.org/wiki/Hollow_earth

How does that follow from anything that's been said in this thread? I've assumed that the overall structure of the Earth is pretty much as science describes it (for instance I mentioned the mantle, the presence of which doesn't exactly square with the concept of hollow planets), but that still leaves plenty of room for things we were previously unaware of. The inside of the Earth is a very big place and it's not as if we've gone over it with a fine-toothed comb.

On the other hand, I feel that hollow Earth fiction has to somehow address the problem that the planet rings like a not-hollow object every time it's struck by an earthquake. As for smaller hollows and caves, I'm not sure how one can address the issues of pressure, plasticity and temperature without simply handwaving them. This is of course also leaving aside the question of how hollow planets can form naturally (if they do) and how any smaller cavities can form and sustain themselves.

[Purple]

Well you did say:

Depending on average how far one can stretch the audience's suspension of disbelief, as well as the conventions of the setting, one could perhaps stash away all sorts of things down there for a near-future civilisation to discover. The idea that there could be immense riches and/or strange (perhaps even eldritch) mysteries hidden under the earth is, to me at least, a powerful one, reminiscent of old tales about the underworld.

So I figured I should provide the absolute extreme in that direction in hopes of getting a reply like the one in your 2nd paragraph.

[Lord of the Abyss]

Additionally, what other benefits could be gained by the ability to easily drill to extreme depths of the Earth's crust? Would it facilitate a revolution in geothermal energy?

The problem with drilling for geothermal energy as I understand it isn't depth; it's finding a way to "drill" sideways. The idea behind creating a geothermal source where nature hasn't done the job for us is to drill two holes, connect them at the bottom and run water through them to pick up heat. If this revolutionary drill technology lets you, say, reliably drill two slanting/curving bores that connect at the bottom then yes, you should revolutionize geothermal energy since if you dig deep enough there's hot rock everywhere. But just being able to dig really deep by itself won't help; we can already dig deep enough, we just can't properly connect the bores.

[Chaotic Neutral]

Additionally, what other benefits could be gained by the ability to easily drill to extreme depths of the Earth's crust? Would it facilitate a revolution in geothermal energy?

The problem with drilling for geothermal energy as I understand it isn't depth; it's finding a way to "drill" sideways. The idea behind creating a geothermal source where nature hasn't done the job for us is to drill two holes, connect them at the bottom and run water through them to pick up heat. If this revolutionary drill technology lets you, say, reliably drill two slanting/curving bores that connect at the bottom then yes, you should revolutionize geothermal energy since if you dig deep enough there's hot rock everywhere. But just being able to dig really deep by itself won't help; we can already dig deep enough, we just can't properly connect the bores.

Pardon my ignorance, but what is wrong with a V shape?

[Lord of the Abyss]

Additionally, what other benefits could be gained by the ability to easily drill to extreme depths of the Earth's crust? Would it facilitate a revolution in geothermal energy?

The problem with drilling for geothermal energy as I understand it isn't depth; it's finding a way to "drill" sideways. The idea behind creating a geothermal source where nature hasn't done the job for us is to drill two holes, connect them at the bottom and run water through them to pick up heat. If this revolutionary drill technology lets you, say, reliably drill two slanting/curving bores that connect at the bottom then yes, you should revolutionize geothermal energy since if you dig deep enough there's hot rock everywhere. But just being able to dig really deep by itself won't help; we can already dig deep enough, we just can't properly connect the bores.

Pardon my ignorance, but what is wrong with a V shape?

Successfully getting two separately drilled holes to actually intersect miles down for one. Something hard enough that instead they've been trying to use explosives to crack the rock between the bottom of the bores to provide passage for the water.