Humankind loves to look up towards new challenges and greater aspirations.
Whether we’re building immense skyscrapers, climbing the tallest mountains, or reaching
for the stars—we never stop striving to better ourselves.
But our world has plenty more to explore and discover even if it means reaching a little
lower.
Perhaps a lot lower.
Deep beneath the sea, buried far underground, and even at the very center of the Earth.
Let’s take a look at seven of the deepest places in the world.
Far beneath the chill waters of the western Pacific Ocean, the Marianas Trench stretches
across the seafloor in a realm that light has never touched.
The deepest point—appropriately called “Challenger Deep”—has been measured at 10,994 kilometres
below sea level, give or take forty meters.
The bottom of the trench was seen for the first time on January 23rd, 1960 by oceanographer
Jacques Piccard along with US Navy Lieutenant Don Walsh from within a cramped bathyscaphe.
They missed the Challenger Deep by a few meters but they were still able to observe the floor
of the Marianas Trench, which was noted to be “light and clear, a waste of snuff-colored
ooze.”
Despite the crushing weight of the water above, the intrepid explorers were certainly shocked
to find life waiting for them at the bottom, in the form of “some type of flatfish, resembling
a sole, about one foot long and six inches across.”
If sixteen thousand pounds of pressure per square inch can’t dissuade life from finding
a way, perhaps there’s a lesson to be learned there.
Later expeditions revealed other extreme forms of life, like giant amoebas measuring ten
centimeters in diameter.
Before the nightmares set in, it might be worth noting that the amoebas didn’t exactly
resemble the single-celled organisms as we think of them, but more like a sea sponge
or coral.
Scientists dubbed these creatures “xenophyophores”, which is science-speak for “they look like
aliens.”
The era of discovery continues even to this day; Hollywood director and science buff James
Cameron performed the deepest solo sub dive into the Marianas Trench on March 25th, 2012.
Using his custom built submersible, he collected samples of the oozy sediment and even captured
3D video of the entire dive—hoping to gain a better understanding of the ocean’s depths
and spur support for future expeditions.
There’s certainly a lot left for us to discover down there.
As long as we don’t anger Cthulhu, we should be okay.
Just a short distance southwest of Johannesburg in South Africa lies perhaps the greatest
achievement in the world of mining since the invention of the pickaxe.
Miners in the Mponeng Gold Mine have been hard at work since 1981, sifting the earth
to produce gold from a vein that averages less than a meter wide.
An interesting dichotomy, when you consider that the Mponeng Gold Mine is the deepest
mine in the world—and it’s all thanks to that relatively tiny golden thread.
Most of the work is done between 2.4 and 3.9 kilometers deep, the latter number being the
current world record for mining depth—and the digging continues, extracting 5,400 metric
tons of rock daily.
Expansion efforts seek to ensure the mine’s long term viability.
Purely a precautionary measure, as in 2012 alone the mine produced around 11,500 kilogrammes
of gold.
That’s $460 million of the golden good stuff.
If you’re still undecided on a career path, perhaps you might consider becoming a miner.
But it’s not all fun and games that far down in the Earth’s crust.
The closer you get to the core of our planet, the hotter things get in turn.
This is an effect known as the “geothermal gradient”, and it’s a constant concern
for the intrepid miners of the Mponeng Gold Mine.
If you were to descend to the deepest point in the mine, the temperature of the surrounding
strata would reach temperatures of up to sixty degrees Celsius.
Consider the harsh, unyielding stone surrounding you—and you’ve got the makings of an oven.
Inhospitable working conditions, for sure.
Thanks to a constant stream of slurry ice pumped through the mine, the temperature is
maintained at a far more bearable thirty degrees Celsius.
Still a sweltering day in the mines, but hey—at least you won’t end up broiled.
Caves have long held a special sort of allure for explorers.
Natural fissures in the terrain which offer nooks and crannies for those brave enough
to test their shadowy depths.
Krubera Cave—located in a particularly porous area of Western Russia known as the Arabika
Massif—isn’t just any old cave.
It bares the unique distinction of being the deepest cave in the world.
It is with no small measure of respect that some cavers have taken to calling it the “Everest
of the caves”—evoking images of the danger and excitement that many find in summiting
the tallest mountains.
Krubera Cave was recognized for its record depth in August of 2004, after a particularly
stoic band of cave explorers followed its twisting path downward to a total depth of
2,080 metres.
It’s the only natural formation known to humankind greater than two kilometers deep,
and it even has a reserve of water at the very bottom known as the “terminal sump”.
That’s as far as the team of cavers could go with the equipment they had with them.
In 2007, and again in 2012, a Ukranian diver by the name of Gennady Samokhin climbed down
to the sump with all the necessary equipment to plunge into the icy water and map the tail
end of the cave.
He earned world records with both dives, and added another ninety-eight meters to the depth
total in the process.
So if you’ve ever fancied a long climb with a brief swim at the bottom, there’s a bloody
scary idea for you to add to your next vacation.
Once you’re through spelunking in Krubera Cave, head east into Siberia to find the next
stop on our whirlwind tour of the world’s deepest places: Lake Baikal.
The depth isn’t the only interesting thing about this crescent shaped reservoir cutting
through the Russian mainland—though it is both the deepest freshwater lake and the deepest
continental body of water to be found on our planet.
Besides reaching incredible depths, there’s plenty of other facts about the lake to get
excited about, especially if you’re a scientist.
Geologically, Lake Baikal is the oldest freshwater lake in the world, and contains nearly 20%
of the world’s unfrozen freshwater reserve.
Not to say that it doesn’t freeze over from time to time—it is Siberia, after all.
The lake and its surrounds are also home to an incredibly diverse collection of flora
and fauna, with some estimates identifying around one 1,340 different species of animals
living harmoniously with upwards of 570 species of plants.
A lush, thriving ecosystem to be catalogued in and around an ancient lake of remarkable
depths—and those eager scientists might even be able to make it home for dinner.
Provided that they live somewhere nearby, of course.
We’re going to have to bend the rules a bit for this next one.
Though the Bentley Subglacial Trench in Western Antarctica isn’t technically covered in
water, it is—well, covered in water.
But not the wet kind.
The trench is actually the lowest point on the Earth not covered by an ocean or other
form of flowing water, sitting at 2.5 kilometers below sea level.
As you might expect, “subglacial” means that it is sequestered beneath the frozen
mass of a majestic glacier.
Surrounded by many other similar stretches of ice all across the Antarctic continent.
This means that the Bentley Subglacial Trench is actually subterranean, though it’s still
a point on the Earth’s surface.
Just not one you could walk to.
I told you we’d have to cheat a bit.
It was named by the Advisory Committee on Antarctic Names in 1961, in honor of Charles
R. Bentley and his contributions to Antarctic research as the chief traverse seismologist
of Bryd Station, between 1957 and 1959.
Seeing as he was the one who led the expedition which first located the trench and recorded
its depth, it seems an appropriate legacy for him to leave behind in the snowy wastes.
Who knows—there could be a secluded spot in Antarctica just waiting for you to slap
your name on it as well.
When in doubt, start drilling straight down and don’t stop until the Earth itself rejects
you.
Not exactly sensible advice, but someone involved with the Kola Superdeep Borehole project must
have heard it somewhere and really took it to heart.
During the Cold War, there was a constant back-and-forth between the United States and
the Soviet Union, each seeking to one-up each other on the global stage.
Scientific endeavors flew fast and furious, one of the results being the Soviets’ decision
to set a drill into the ground of the Kola Peninsula and dig as deep as possible.
There were certainly valid scientific reasons for the project, but it almost sounds as if
they were just waiting for an excuse to do so.
The drilling began in 1970 and didn’t stop until 1994, producing what we call today the
Kola Superdeep Borehole, the deepest hole ever drilled to date and the deepest artificial
point in the world, reaching a mind-boggling twelve kilometers into the crust of our planet.
That’s deeper than even the Challenger Deep.
In the end, the borehole encountered the same issue as the miners in the Mponeng Gold Mine—things
get really hot that deep underground.
Temperatures at the end of the shaft climbed to around 180 degrees Celsius—no, not Fahrenheit,
but Celsius.
That’s a brain-melting 356 Fahrenheit.
The equipment simply couldn’t continue to function in those conditions, and so the Kola
Superdeep Borehole had reached its end.
But rumors continue to swirl about what exactly brought about the conclusion of the drilling.
There are campfire ghost stories about microphones lowered into the shaft, which recorded the
sounds of tortured screams.
What’s really going on at the center of the Earth?
Well let me tell you…
At the very center of our planet lies a sphere of solid iron—at least, as best we can tell
with current data.
Deeper than the molten mantle and liquid metal outer core, the inner core seems to be formed
of a massive, non-uniform ball of iron.
It is this core, and the extreme heat as a result of several factors working in tandem,
that serves to heat the planet from within.
The same heat which wards off any attempts to burrow through the crust; it’s as if
the underworld is feverously trying keep us at bay.
There must be something going on down there.
The estimated temperature at the boundary between the molten metal of the outer core
and the solid inner core is around 5,600 degrees Kelvin.
To put that in some perspective, the temperature of our Sun’s surface is 5,800 degrees Kelvin—only
two hundred more, some predict that the Earth’s core might even be hotter than the surface
of the sun.
Thanks to pressure, friction, and radioactive elements, the Earth essentially has a miniature
sun burning at its very heart.
Perhaps we will never get to see the very core of the Earth with our own eyes, but we
can dream.
And every crevice, borehole, or trench we discover can bring us that much closer to
understanding the unsearchable depths beneath us.
And no matter how deep we go, it can only get warmer and brighter once the darkest places
are behind us.