In 1970, Soviet scientists launched one of the largest and most daring drilling and mining
projects ever attempted.
A drilling effort began on the Kola Peninsula that would go on to dig deeper than any other
in human history, breaking a Guinness World Record that stood for a long time.
Over twenty years after all digging stopped at the borehole, which was subsequently welded
shut, it is still recognized as a grand science project that resulted in both significant
scientific findings and urban legends that wouldn't be out of place in a current horror
film.
The Earth's mantle is over 1800 miles thick, and its radius is roughly 4000 miles.
As incredible as it may sound, the mantle is the primary driving force behind Earth's
ongoing evolution.
All or nearly all of Earth's history as recorded by geologists is there.
In 1958, scientists launched Project Mohole, the first of several attempts to penetrate
the mantle.
For this mission, American engineers dug a hole in the seabed off the coast of Guadalupe,
Mexico, in the Pacific.
Unfortunately, the drills never made it to the mantle because Congress shut off financing
in 1966.
So, if we were to dig all the way to the heart of the planet, what would we discover?
Well, the Soviet Union's project mentioned at the beginning of the video can give you
a general notion, and today we'll tell you how it all started and why the world's deepest
hole was recently sealed.
During the Cold War, the Soviet Union undertook a scientific drilling operation known as the
Kola Superdeep hole.
It could be found in the Pechengsky district, which is near the Russian border with Norway
on the Kola Peninsula.
The project was initiated with the intention of penetrating the Earth's crust as deeply
as possible.
Beginning on May 24th, 1970, a Uralmash-4E drilling rig was used, and later on a Uralmash-15000
series rig was used for the same purpose.
In 1979, the Kola Superdeep hole was the deepest hole ever made by humans.
The 23-centimeter-diameter boreholes were bored by branching off from a central structure.
In the year 1989, the deepest hole reached a depth of 12,262 meters and was deemed the
deepest manmade point on Earth.
It is the world's deepest borehole in terms of real vertical depth.
In terms of measured depth, it remained the world's longest borehole for twenty years,
until it was exceeded in 2008 by the 12,289-meter AL-Shaheen oil well in Qatar.
Uralmash-4E, a serial drilling rig normally used for oil drilling, was modified so that
it could drill to a depth of about 7,000 meters before drilling began in 1970.
In 1974, a brand-new, custom-made drilling rig named the Uralmash-15000 was brought in.
Given the new goal depth of 15,000 meters, the name was chosen accordingly.
Previously, the Bertha Rogers Hole in Washita County, Oklahoma, United States held the record
for deepest hole in the world, but in June 1979, the Kola Superdeep hole surpassed it.
The incredible depth of the Bertha Rogers Hole was 9583 meters.
In October 1982, the depth of the first hole was determined to be 11,662 meters, and in
January 1983, drilling for the second hole began from the 9300-foot-deep first hole.
In the same year, the depth of the second hole drilled reached above 12,000 feet.
This was such a huge success that drilling was halted for a whole year as a means of
celebration.
During this period, the site hosted countless scientific and celebratory visitors.
This hiatus played a role in the subsequent failure when drilling restarted in 1984.
On September 27th, 1984, a 5,000-millimeter portion of the drill string twisted off and
was left in the hole at a depth of 12,066 meters.
In September of 1986, at a depth of 7,000 meters from the initial hole, further drilling
operations commenced.
In 1989, this third hole went down 12,262 meters.
Although this was less than geologists had hoped for, it was nevertheless a huge accomplishment.
After experiencing yet another breakdown in June of 1990, drillers were forced to begin
a fourth hole at a depth of 9653 meters in the third hole.
At 11,882 meters, it was halted in April of 1992.
In April of 1994, after reaching a depth of 8278 meters in the previous hole, work continued
on the fifth hole.
Because of financial constraints, drilling was put on hold for good in August of 1994.
Unusually high temperatures were recorded at such a depth and location.
The temperature was closer to 180 degrees Celsius than the predicted 100 degrees Celsius
by the experts.
After further consideration, they concluded that digging deeper was impossible.
At this depth, the Earth's density suddenly dropped, while its porosity dramatically increased.
Due to the extreme heat, the rock underneath had become virtually flexible, making drilling
nearly impossible.
Since the depth of the Baltic Shield continental crust is close to 35 kilometers, the Kola
Superdeep drill only made it about a third of the way through it, to the Archean rocks
at the bottom.
Geophysical studies have been conducted on the side for this project.
When researchers looked for a change in composition from granite to basalt at depths of around
7 kilometers, they were shocked to find none.
It was eventually deduced that the metamorphic transition of the Granite Rock was responsible
for the observed variation in seismic wave velocity.
They determined that the metamorphic transition in the Granite Rock was the true cause of
this seismic wave velocity variation.
In addition, the granite was deeply cracked and saturated with water; unlike surface water,
this water came from deep crust minerals but was unable to reach the surface due to an
impenetrable layer of rock above it.
Massive volumes of hydrogen gas were yet another unusual discovery.
It was so plentiful that experts described the outflowing drilling mud as boiling with
hydrogen.
In 1992, a worldwide geophysical experiment was successful in acquiring a seismic crustal
cross section from the well, the working group Kola 92, and a large number of specialists
from a variety of fields.
Researchers from the Universities of Edinburgh and Glasgow in Scotland, the University of
Bergen in Norway, and a number of Russian Earth science research organizations participated.
David Smythe, professor, filmed the experiment in great detail.
When drilling came to an end in 1995, the scientific teams were moved to a federal state
unitary subsidiary business named Kola Super Deep, where they refocused their attention
on studying the exposed crust in great detail.
The scientific group disbanded for good in 2007.
The equipment was partially liquidated and transferred in part to a private corporation.
Even the firm was liquidated in 2009 since it was not profitable.
The Kola Superdeep drilling site was abandoned in its entirety.
Nonetheless, the Kola Superdeep borehole SG-3 still holds the record for the deepest artificial
point on Earth, at a staggering depth of 12,262 meters.
In all honesty, the scientists did not expect to discover any traces of life so far beneath
the Earth's crust.
As with every other location they've explored, nature's enigmatic and potent ways astonished
them.
At that depth, no living organisms were found, however plankton fossils were discovered.
The geological information gathered from this incomprehensibly deep hole may be eye-opening,
but it was the paleontological discoveries that shocked everyone.
The fossils were found at a depth of over 6.4 kilometres (2 miles) in the Kola super
deep borehole and are thus at least 2 billion years old.
Microscopic plankton fossils were discovered in surprisingly good form, considering the
harsh circumstances of the hole in which they were discovered.
From these fossils, researchers have identified at least 25 different types of plankton living
so far below the surface.
In the opinion of experts, if they had continued their search, they would have discovered further
species.
Surrounding these organisms was organic material that was surprisingly resistant to the environment
in the hole.
Although the collapse of the once-powerful Soviet Union was widely cited as the reason
for the drilling's suspension, most experts now believe it was only one of several variables.
Given the presence of water, some scientists think it's only fair that life of some kind
figured out how to adapt and survive there in the distant past.
Hydrogen and oxygen atoms were squished out of the rock by the intense pressure, but the
water had nowhere to go because of the impervious rock layer above.
The finding of these plankton fossils has been cited by many conspiracy theorists as
the reason Russia decided to abandon the project.
However, this is not the true reason why the Kola Superdeep drilling project was abandoned.
The truth is that conditions become too hot to continue drilling.
In fact, it was claimed at the time that the heat was quite damaging to the machinery.
Nevertheless, some have postulated that the Soviets continued digging long after their
nation was split into independent countries; this is factually incorrect, given there is
proof of the hole being sealed and anyone may actually visit the site to prove it.
Maintaining the bore got very challenging.
It was like to attempting to maintain a hole in the center of a pot of boiling soup.
This digging also revealed that sedimentary rocks discovered at depths of up to 6800 meters
date back to the Proterozoic period, which began around 2.4 billion years ago.
Evidence suggests that the granitic layers found deeper in the earth were deposited as
early as the first geologic era, 2.7 billion years ago.
Besides the expected hydrogen and oxygen, the bore hole also revealed the presence of
lithium, nitrogen, and carbon dioxide, indicating that these elements are also abundant on Earth.
Even though the Earth's core is the thinnest layer, humanity have still not drilled all
the way through it.
Even if we tried to drill all the way to the core of the earth, we'd have to bore through
solid iron, which is easier to do in theory than in practice.
Due to the near absence of gravity near the Earth's core, this would be extremely challenging.
Despite its impressive depth, the KOLA super deep hole only penetrated about a third of
the way into the Earth's crust.
In any case, that was the furthest anybody had been up to that point.
The previously fascinating Kola Superdeep borehole is now merely a magnet for thrill-seeking
visitors.
There were many highs and lows for the project until it was finally abandoned in 2005 owing
to a lack of resources.
In spite of the fact that the drilling and research equipment used at this location has
been discarded, the data gathered from the hole is still being studied by experts all
over the world.
A metal cap was welded over the opening and it is still there today.
If scientists succeed in drilling to the center of the Earth, what do you think will happen
and what will it reveal?
Leave a comment and let us know.