Deep in western Russia, the frigid desert
contains the remnants of one of the most ambitious scientific experiments ever performed. It's a ruin now, a wasteland of jagged metal
and crumbling concrete. If you search around long enough, you will
find a rusted disc, bolted to the earth. So unassuming that you might even try to pick
it up. But you won't be able to. It's the welded-shut cap of a borehole that
plummets more than twelve kilometers into the earth, deeper than the deepest depths
of the ocean. It's the deepest hole on earth. It's called the Kola Superdeep Borehole, and
its existence has nothing to do with petroleum exploration. Rather, when drilling began in 1970, Soviet
scientists hoped to eventually drill down to fifteen thousand meters in order to gain
a better understanding of the nature of the Earth's crust. Because the truth is, we know less about what's
under our feet than what's on the other side of the solar system. They drilled on and off for twenty-four years,
and though they didn't quite reach their goal when work came to a halt in 1994, the engineers
had reached a record depth: 12,262 meters, a record that still stands today. Two decades later, the Kola Borehole remains
a remarkable technological and scientific acheivement. To drill it, engineers devised a new method
by which only the drill bit at the end of the shaft was rotated, the lubricant, in this
case, pressurized drilling mud, was pumped down through a custom drill bit, allowing
it to spin. Instruments had to be invented to take measurements
at the bottom of the hole. What did we learn by drilling a third of the
way through the Baltic continental crust? For one, there's water down there, at depths
scientists didn't believe water could be found. They suspect that the water formed from hydrogen
and oxygen that were squeezed out of rock crystals due to crazy high levels of pressure
that far down. Unlike groundwater, this water originated
from the rock minerals themselves. Never before had this been observed. Also surpising, how about microscopic fossils
discovered by Russians at depths of up to 6.7 kilometers? Researchers catalogued twenty-four species
of single-cell plankton microfossils over the course of the project, and they weren't
found in the kinds of deposits we're used to finding them, like limestone and silica. These were covered by organic carbon and nitrogen
compounds, preserved thanks to those high pressures and high temperatures so far below
the surface. As for those temperatures, by the time the
engineers broke through the twelve kilometer mark, where rock samples were dated at 2.7
billion years old, the heat became a major issue. Researchers thought the temperature of the
rocks would be about 100 degrees Celsius. What they found were temperatures in excess
of 180 degrees. It was this heat that caused the drilling
to come to a stop. Engineers described the rocks at 12 kilometers
as acting more like plastic than rock. Of course, as astonishing as this project
was, the Kola Superdeep Borehole only made it through a tiny fraction of the Earth's
layers. 12 kilometers is three times as deep as humans
have ever gone, but the eath's mantle desn't even begin until about 35 kilometers below
the surface. The mantle then continues for another twenty-eight
hundred kilometers; the center of the inner core: more than sixty-three hundred kilometers
below the surface. Put another way, this borehole which took
24 years to drill, made it roughly 0.002 percent of the way to the middle of the Earth. It's a big planet, you guys. Thank you for watching this SciShow Dose,
especially to our Subbable subscribers. To learn how you can support us, just go to
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SciShow Space, for the latest in space news, and weekly forays into the fascinating depths
of the cosmos. If you have any questions, you can find us
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getting smarter with us, you can go to youtube.com/scishow and subscribe.
When you're trying to educate on science, I think you should get your maths correct: "To put another way this bore hole made it 0.002% of the way to the center of the Earth" Or to put it mathematical terms; the bore hole made it 0.2% of the way to the center of the Earth! 12.5/6,300 is appox 0.002 = 0.2%
Anyone know of a YouTube channel like this, just better?
ITT People who hate the guy in the video, people that don't understand basic science, and more mom jokes than I usually see in a month.
So this is probably going to sound like a painfully scientifically ignorant question, so pardon me in advance (as I am no geologist!).
But why couldn't we ever dig a wide hole, that spanned far deeper into the Earth?
It seems to me that a small width borehole (like this one the Russians dug) is probably extremely difficult/impossible, since it doesn't really allow for the heat to vent/dissipate, thus melting your digging instruments eventually.
But... if you have a really wide hole, that you just keep making deeper and deeper, it seems like it could vent the heat, and then cool somewhat, and then allow you to continue digging deeper.
And I also wondered:
If we ever tried to create such a hole in the Earth, would we reach a point in which we would be at risk of creating a supervolcano: in which the pressure of molten lava-rock would just take advantage of the giant hole and surge upward?
If we've only explored 12km of the surface, how do we know all that shit about the center of the earth?
https://www.youtube.com/watch?v=zz6v6OfoQvs#t=190
I want to drop a penny down it.
They messed up be using a drill. They should have gotten one of those subterranean crafts they used in the movie "The core"
he talks like that other guy. why do so many youtube hosts talk in that style?
I was really hoping to see the inside of that hole.