
The deepest hole we have ever dug - otoolep
https://www.bbc.com/future/article/20190503-the-deepest-hole-we-have-ever-dug
======
lb1lf
Pedantry mode: That hole is drilled, not dug.

The deepest hole we've dug is probably the Mir diamond mine in Siberia, at
525m [0]

(A quick internet search will probably say that the Bingham copper mine in the
US is deeper, but that was dug at the bottom of an existing canyon, giving it
a head start; the Mir mine started... Well, basically with a bunch of guys
with shovels in the middle of the tundra.

[0] [https://www.atlasobscura.com/places/mir-diamond-
mine](https://www.atlasobscura.com/places/mir-diamond-mine)

~~~
growlist
Well ackshually... :)

Shout out for the deepest hand dug well:
[https://www.mybrightonandhove.org.uk/places/utilities/woodin...](https://www.mybrightonandhove.org.uk/places/utilities/woodingdean-
well/woodingdean-well)

~~~
justinclift
That page says the well was 1285 feet (~390 meters). So, the Mir mine (525
meters) does seem deeper.

~~~
lb1lf
-True, but at some point I believe it is safe to say that the Soviets started using heavy machinery - an option denied the workhouse inmates who dug the well.

(This is where the 'deepest hole dug' contest gets a whiff of 'No true
Scotsman...')

On some levels I find the well more impressive than the mine, though. A 4ft
diameter hole dug 1285ft deep means some 400 cubic meters of dirt was removed.
By hand. That's an awful lot of blisters by anyone's standards.

------
edf13
The latest project to drill through the mantle...

The deep sea drilling vessel Chikyu will drill through the crust where it is
the shallowest using tech which wasn't available in any of the previous
attempts. Looking forward to this one starting!

[https://www.jstage.jst.go.jp/article/jscejam/71/2/71_I_3/_ar...](https://www.jstage.jst.go.jp/article/jscejam/71/2/71_I_3/_article)

~~~
heydabop
My wife and I were talking about this borehole a few weeks ago and wondering
why similar projects hadn't been undertaken with newer technology. So thanks
for this, interested to see how it turns out!

------
mmmBacon
Link to Lotte Geevan’s recording in the German borehole. According to the
article the rumbling sound recorded was unexpected.

[https://vimeo.com/80266870](https://vimeo.com/80266870)

~~~
platz
> It’s not clear exactly what you hear on Geeven’s recording. She guesses it
> could be something small like a data transmission that is resonating, but
> she can’t be sure. In a Heisenberg-ian twist, it seems possible that some of
> the sounds were created by the devices themselves. "Exactly knowing what it
> is is not important I believe," she says. "Mysteries are important. They act
> as engines for new thoughts and ideas."

~~~
SketchySeaBeast
Were are you pulling that link from? I'm interested to learn more about this -
I'm also interested in the technical details about things like what dB the
sound was originally. That's quite the rumble - I suspect there was quite a
bit of amplification involved.

~~~
platz
[https://www.wired.com/2014/01/an-artist-records-the-
mysterio...](https://www.wired.com/2014/01/an-artist-records-the-mysterious-
rumblings-of-middle-earth/)

~~~
SketchySeaBeast
Thanks!

> "I later learned that blind people can 'hear' thunderstorms because the low
> frequency can be sensed in the body"

Huh. Amazing no one has commented on that.

~~~
finnh
I suppose she meant deaf people? Not too surprising - a loud thunderclap
rattles windows, and seems likely to have low enough tones to be sensed
internally. I remember reading about deaf sports teams using low-frequency
gongs in place of whistles.

~~~
SketchySeaBeast
Yeah, I assume deaf as well. Just funny that neither she nor wired caught it.

------
platz
So if you drill through the crust to the mantle, will magma come up the hole?
Will you create a little volcano?

~~~
jofer
First off, this borehole isn't that deep. Over the continents, you'd need to
drill to 40-70km to reach the mantle (sometimes even 100km). However, oceanic
crust is much thinner. It is technically feasible to drill into the mantle in
ocean basins, where the mantle can be only a few km below the seafloor.

Regardless, the mantle isn't molten. It's different types of rocks, but
they're still rocks.

In fact, the mantle is exposed at the surface in a handful of locations (and a
good chunk of the ocean floor). We have learned a lot from what's exposed at
the surface, but these rocks have been significantly chemically alerted. Many
of the minerals we expect to be there are unstable at near surface conditions.
We'd learn a _lot_ from "fresh" mantle rocks

If you were to maintain the same temperature but drop the pressure to surface
conditions, yes, deep mantle rock would melt. A hole with nothing in it going
deep enough would cause a volcano (even if it didn't hit the mantle). However,
not all of the mantle is hot enough for that to occur. (Again, the mantle is
quite shallow beneath the oceans) We also have to keep the pressure at the
bottom of the hole the same as the rock around it, so a well doesn't usually
release pressure.

At any rate, in any case where you'd try to drill into the mantle, it would be
impossible for a volcano to form.

All that having been said, geothermal drilling in Iceland has hit magma
chambers by accident and caused a "mini volcano".

~~~
Andrew_nenakhov
If the hole is not wide enough, like less than 1m in diameter, then rising
magma would likely cool off and seal the shaft long before the flow would
reache the surface.

~~~
K0SM0S
To be fair, it probably isn't the easy approach to drill so thin.
Paradoxically (or not), the bigger ones are less of a hassle to manage as you
dig deeper.

------
pontifier
It's interesting what they said near the end... Most of the cost of a project
like this isn't going to be spent on the actual drilling. Most of it will go
into supporting the people who are supporting the infrastructure that enables
the drill team to do the work of doing the actual drilling...

I've just finished applied for a government grant, and am starting to realize
just how inefficient these projects need to be to support the people doing the
work.

I've probably underestimated my own costs by a lot, and allocated _too much_
toward the actual science I'll be doing.

------
unlinked_dll
I was under the impression that the Kora borehole went unfinished because the
drill broke due to temperature (7 miles down and you're talking hundreds of
degrees C), not the breakup of the Soviet Union.

~~~
alamortsubite
While the article says the time at which drilling was stopped was after the
breakup, it gives the reason as the high temperatures encountered.

"Then it was the turn of the Kola Superdeep Borehole. Drilling was stopped in
1992, when the temperature reached 180C (356F). This was twice what was
expected at that depth and drilling deeper was no longer possible."

------
choeger
How long does it take to dig a hole to the mantle? Could we drop nuclear waste
in such a hole?

~~~
Cthulhu_
I don't think heating up nuclear waste would be a good idea. Even if you don't
reach the mantle, it's hundreds of degrees (celsius) down there already.

That said, putting nuclear waste deep underground and sealing the hole is
probably the best best.

~~~
_Microft
I would like to argue that waiting for partitioning and transmutation
technology to mature and temporarily storing the waste until then makes more
sense than putting nuclear waste into a place where we can not easily (or at
all!) reach it when we can use it (and thereby actually solve the problem).

Some half-lifes are so long that just any progress over a fraction of these
time-scales should be be enough to be better off to wait for the tech to be
ready than to bury the material.

~~~
progval
"temporarily storing the waste" is mostly what the US have done since the late
70s.
[https://en.wikipedia.org/wiki/Dry_cask_storage#United_States](https://en.wikipedia.org/wiki/Dry_cask_storage#United_States)

Yucca Mountain was supposed to be the solution this temporary storage; but the
budget for Yucca Mountain got suspended, so the US are back to the temporary
solution.

But postponing forever in the hope of a better solution is a bad solution;
because in the meantime they are in unsafe locations.

~~~
Kaiyou
Not forever, just for 200-500 years.

------
Scirra_Tom
Would drilling holes deep enough theoretically allow us to harvest thermal
energy on a meaningful scale?

~~~
cryptica
When the article mentioned that the temperature was twice what they had
expected, I wondered the exact same thing.

Could they cover the hole, pour water into it and use air pressure changes in
the hole to generate electricity? There must be a way to make the hole air
tight. I suspect that the rock near the bottom of the hole would already be
air tight.

Also I never understood why steam engines release all the hot stream into the
air? Doesn't that waste energy to let the hot steam out? Isn't it better to
keep the heat trapped inside the system and generate electricity from the
pressure only?

~~~
Turing_Machine
> Also I never understood why steam engines release all the hot stream into
> the air?

They don't. All practical steam engines have condensers that recover most of
the water and as much of the heat as current technology and the laws of
thermodynamics allow.

~~~
m4rtink
In steam trains it is often injected to the chimney to increase draft, forcing
more air through the firebox, improving combustion. This of course uses up a
massive amount of water.

For this reason most steam engines in ships and elsewhere generally did have
condensers & reused the steam as feedwater, as you describe.

------
thamer
How long would it take to fall 40,230 feet? I'm guessing the drill doesn't go
straight down, but it's still a fun thought experiment.

This free-fall calculator[1] (with air resistance) reports a fall duration of
229 seconds (3m49s) with 121mph velocity for a 72kg mass with the default air
resistance coefficient as used in skydiving.

[1]
[https://keisan.casio.com/exec/system/1231475371](https://keisan.casio.com/exec/system/1231475371)

~~~
animal531
I imagine that if the hole isn't that wide then it would be harder to displace
air, meaning that you should fall slower.

------
andrewaylett
There is, as they say, an XKCD for every situation:
[https://xkcd.com/1330/](https://xkcd.com/1330/)

And showing relative depths -- it always surprises me that modern oil wells
aren't actually _all_ that shallower:
[https://xkcd.com/1040/](https://xkcd.com/1040/)

~~~
umvi
> it always surprises me that modern oil wells aren't actually _all_ that
> shallower

There is a theory that oil is actually generated as a by product of the mantle
itself, not by buried prehistoric plants.

If that's the case, oil could truly be a limitless resource, which is bad news
for the climate.

~~~
MisterTea
> There is a theory that oil is actually generated as a by product of the
> mantle itself, not by buried prehistoric plants.

Sounds like more like alchemy than actual science. What magical process
transmutes rock into long chain hydrocarbons?

~~~
umvi
I'm not saying I believe it, but the mantle does contain natural hydrocarbons
and it's not _just_ "rock" \- it's a very slow moving liquid under immense
temperatures and pressures. Who knows what kinds of reactions might happen on
mantle-crust (or other) boundaries.

~~~
pixl97
And it helps to remember that hydrogen is the most common element in the solar
system. Its not common on the surface, but huge amounts of it are trapped in
the earth's interior.

~~~
a1369209993
It's not hydrogen that's the limiting factor, it's the carbon. Carbon, like
silicon (in rock), tends to bind to oxygen whenever possible. So long-chain
hydrocarbons would have to in highly anoxic regions. And there's also the
issue of reacting with all that abundant hydrogen to form methane, although
I'm not sure offhand which direction the binding energy difference favors on
that one.

------
syspec
“What was clear for the experience of the Russians was that you have to drill
as vertical as possible because otherwise you increase torque on the drills
and kinks in the hole,” says Uli Harms. “The solution was to develop vertical
drilling systems...”

Great article, but does anyone have any insight as to what those techniques
were?

~~~
opwieurposiu
Instead of turning the bit by turning the entire string of pipe, you can turn
only the bit with a mud-motor.

[https://en.wikipedia.org/wiki/Mud_motor](https://en.wikipedia.org/wiki/Mud_motor)

------
ilaksh
Is there any potential for energy generation from the high temperatures?

~~~
Jamwinner
Or ill effects to cooling the inside of the earth? I like the idea of
geothermal, but nothing is free.

------
snshn
[https://www.youtube.com/watch?v=FWVNDfDSE44](https://www.youtube.com/watch?v=FWVNDfDSE44)

~~~
dls2016
Did you know the hole's only natural enemy is the pile?

[https://www.youtube.com/watch?v=DERjNPnr31Q](https://www.youtube.com/watch?v=DERjNPnr31Q)

------
tomjuggler
Anyone else click on the link thinking it was an article about Brexit?

------
K0SM0S
Obligatory, some forward-looking ('hard' sci-fi) physics and observations
about drilling to the Earth core, by _Isaac Arthur_.

[https://youtu.be/jZQP2oNDkAM](https://youtu.be/jZQP2oNDkAM)

Warning: nerd alert!

------
DonHopkins
Cards Against Humanity got people to donate more than $100,000 to dig a big
hole for no reason at all. Maybe scientists should try funding a deep bore
hole for science by live streaming it.

[https://www.independent.co.uk/news/world/americas/cards-
agai...](https://www.independent.co.uk/news/world/americas/cards-against-
humanity-hole-dig-livestream-watch-video-a7444101.html)

~~~
drharby
I want to know what the environmental impact on that hole...i mean where is
the humor in destroying the planet just because we can?

That hole makes me unnervingly angry. And I can't be the only one.

~~~
bananabreakfast
This is extremely reactionary to the point you must be trolling.

"Destroying the planet"? Come on. It's a hole in the ground. We make a hole
ten times bigger than this every time we build a building.

~~~
drharby
I am not trolling.

this is the same forum where people minimize their consumer garbage output to
one bag a year and reduce aviation usage to reduce carbon footprint. I find it
EXTREMELY condescending that you ridicule my opinion. Whats the scope for
scales of environmental impact that matters?

Every single construction project in an area where an endangered species
lives, the USAF must conduct an environmental impact study for said species
from the project, even if its a toilet.

I am very much extremely reactionary, this is a news forum. People post news
and react to it.

~~~
DonHopkins
One environmental impact of the hole is that it just caused you to unnervingly
outgas huge quantities of hot carbon dioxide and stinky methane into the
atmosphere, years after it was dug, and expose yourself as a troll.

Why don't you donate some money to charity to offset your fake moral outrage?

What I don't understand is why you're so clearly and idealistically virtue
signaling, and taking other people's commentary so deeply personally, while
your profile says:

>This is my avatar for participating in a community full of idealists, virtue
signallers, hardworkers, and paid advertisers.

>To take personal any of my commentary is a folly of the reader.

You sound like a troll to me.

PS: You misspelled "signalers" and "hard workers", and just forgot two
apostrophes. Did you know that your web browser has a built-in spelling
checker and corrector? Look for misspelled words with squiggly red lines
underneath them, then click the right mouse button on them to pop up a menu
with correct spellings. Also, you should brush up on the simple easy-to-
remember apostrophe rules -- it will improve your trolling:

[https://grammar.yourdictionary.com/punctuation/apostrophe-
ru...](https://grammar.yourdictionary.com/punctuation/apostrophe-rules.html)

~~~
drharby
Everything about this comment is a personal attack and sidesteps my real
concern--the flagrant disregard for the environment just because someone can
do it.

And Don I have to tell you, I am not a troll and I have to ask what crime did
I commit expressing myself?

Was the post script necessary?

Maybe I get heated because this forum claims a standard is being held while I
see bias persist

Maybe i believe it is important in a healthy democracy that the right
conversations happen.

Maybe I hate bullies. You def. Are being a bully.

You disregard a real talking point on how little liability we hold people to
disrupting land, and just attack me, AND YOU CLAIM YOU CAN BC YOU PERCEIVE ME
AS A TROLL.

I stand by my profile description bc this is a diverse community.

I have a question for you, what is your purpose of your rant? To make me feel
bad and you feel superior?

~~~
DonHopkins
Oh, boo hoo. Bullying and hate speech, huh? You're the only one brought any
"hate" into this conversation: you just used that word five times, called me a
bully, and said you hate bullies (therefore you hate me). That clinches it.
You're definitely an angry reactionary troll. Keep digging that fine hole
you've made for yourself there.

PS: That's "PostScript" (TM Adobe).

~~~
dang
Dear Don, please go easier. You don't know your own strength sometimes.

------
shoptechmedia
When the Russians started to drill they claimed they had found free water –
and that was simply not believed by most scientists. There used to be common
understanding among Western scientists that the crust was so dense 5km down
that water could not permeate through it

------
passwordreset
The deepest hole we have ever dug (bbc.com) = Doctor Who, season 12.

(j/k)

