A rusty metal cap now covers what was once touted as the world's deepest hole. That title has since been surpassed first by Qatar's oil rig that falls 40,318 feet beneath the earth's surface. This was then followed by the well situated in proximity to the Russian island of Sakhalin that is 40 502 feet deep.
We always revisit the original deepest hole located on a remote north-west Russian peninsula because it was the first to break the 40,000 feet barrier. There is also still a world of lessons to learn from the hole that took Russian scientists decades to drill only to uncover unexpected finds.
Digging Beneath The Surface
The quest to discover the earth's deepest secrets is an unending one. It goes back to 1957 when we launched the first artificial satellite hoping to discover proof of life in space, or at the very least find out more about the stars. Now, we have private companies, like Elon Musk's SpaceX, focused on space exploration, and we are learning more each day about the universe.
While we might seem obsessed with figuring out what lies beyond the skies, we sometimes forget to look below the earth's surface. Teams of scientists have dedicated their time to exploring the equally mysterious secrets hidden right beneath our feet.
Exploring The "Deep Frontier"
Most of us believe that we have far greater knowledge about space compared to what exists beneath the Earth's surface. It all goes back to the highly publicized space race between the U.S.S.R. and the United States while the Cold War waged.
Much like the space race, the time started ticking in 1970 with the dueling nations striving to explore the unknown "deep frontier." The main difference this time is that Americans didn't emerge the victors in the subterranean quest. However, it's a matter of opinion whether or not this was a race that was truly conquered.
Journey To The Center Of The Earth
Excavations into the Earth's crust started towards the late '50s. Competing Soviet and American scientists started putting together elaborate experiments structured to probe the ground underneath. The Earth's crust is believed to stretch out 30 miles towards the core, starting with the dense shell that gives way to the mantle and holds its fair share of wonders.
However, these scientists aimed to explore the mysterious inner layer, which constitutes 40% of the Earth's mass. The best place to start the project was underwater, and the Americans took the lead by traversing the Pacific Ocean.
Attempting To Breach The Mohorovičić Discontinuity
Just close to Guadalupe, Mexico, a group of U.S. engineers, going under the title the "American Miscellaneous Society, drilled through the Pacific Ocean's bed in 1958. They were attempting to breach the Mohorovičić discontinuity (also known as Moho), which is the boundary that separates the Earth's mantle and crust.
Hence the reason why it was dubbed Project Mohole. It was feasible to drill in the ocean instead of the land because the seafloor is much thinner and closer to the mantle. They reached a depth of about 600 feet, but that is as far as they ever got. Eight years later, the project funding was cut.
A Quest To Understand More About The Mantle
The Soviets picked up the mantle on May 24, 1970, when a team of researchers started drilling into the earth. The location was the Pechengsky District located on the Russian Kola Peninsula. The mantle is essentially the engine that drives our planet's evolution, and it holds geological records of much of what the Earth has gone through in history.
Benjamin Andrews, a curator, and geologist for the National Rock Ore Collection housed at the Smithsonian, explains that understanding the mantle and how it behaves gives us more knowledge about earthquakes and volcanoes.
Targeting A 49,000-Foot Depth
The Soviets were aiming at reaching a depth of at least 49,000 feet, and they employed the use of specialist equipment to get the job done. They made use of the Uralmash-4E drilling rig and later switched to the Uralmash-15000.
They started by digging a series of boreholes that branched from a primary cavity. Before the Earth science projects commenced, what we knew about the Earth's crust and its composition had been hypothesized. The projects produced unprecedented geological data. As they inched their way down, Americans were also making strides of their own.
The World's Former Deepest Hole
The Lone Star Producing Company started working on an oil-exploratory project in 1974. Their dig site's location was in Washita County, Oklahoma, and the resulting well was dubbed the Bertha Rogers hole. Lone Star started drilling in October 1972, and about 18 months later, they had reached 31,441 feet below the ground.
It was considered a human-made marvel at the time because it was the planet's deepest hole. However, as the Soviets continued working on their own Earth science project, it wasn't long before they surpassed that record.
Record-Setting History
Lone Star wasn't successful in their mission, but their efforts went down in record-setting history. The project encountered technical problems that brought it to a standstill. They didn't discover any commercial hydrocarbons, but instead, they hit a molten sulfur deposit. It solidified and encased the drill string, which led to the loss of the bottom-hole assembly.
The Bertha Rogers well still held the title of the world's deepest hole for five years, before the Kola boreholes, also referred to as the SG-3, broke the record. By 1983, the Kola project breached the 39,000-foot mark taking over the worthy title of the world's deepest hole.
Vertical Drilling System
The researchers at Kola downed their tools for nearly a year after achieving the milestone. The site welcomed visitors who wanted to set their eyes on the fascinating trench, and it also served as the site for numerous scientific studies.
One of the lessons learned from the Soviets, when the German Continental Deep Drilling Program kicked off in 1990, was the need to aim at drilling vertically. They came up with vertical drilling systems that are currently an industry-standard, that avoid kinks by increasing torque on the drills. Going back to the Soviets, the idle time affected the drilling process when they resumed in September 1984,
Restarting The Process
When drilling resumed, they reached 39, 587 feet below the Earth's crust when the trouble started. Part of the drill string got crumpled off and fell in the hole. The researchers didn't abandon the project entirely, but they restarted the drilling process at 23,000 feet.
By 1989 they got to a record-breaking 40,230 feet below the ground, which was an incredible 7.5 miles into the Earth. It encouraged the team working on the Kola project, and they were optimistic that they could push the limits and get to 44,000 feet in late 1990.
An Unexpected Turn Of Events
The drilling was projected to get to the targeted 49,000-foot depth by early 1993. However, the team couldn't have predicted the unexpected turn of events that they would run into tucked away beneath the tundra in Russia.
It seemed like the closer the team inched to the center of the Earth, the more they disproved theories once held about the conditions harbored within the ground below. More than two decades had passed since the project kicked off, and the Soviets had impressively managed to drill 7.5 miles into the Earth's crust.
Soaring Temperatures
For the first 10,000 feet, the temperatures remained steady inside the borehole and within the realms of what the researchers had expected. Once they dug beyond that depth, the heat soared much faster than expected.
When drilling was approaching the target 49,000-foot target, temperatures within the hole had shot up to 356 °F, which was 144 °F hotter than expected. It's estimated that temperatures can soar up to 1,600 °F at the point where the mantle and crust meet. At the bottom of the mantle, temperatures can reach a scorching 4,000 °F.
Pliable Rock
The scorching temperature wasn't the only surprise the researchers stumbled upon, but they found that the rocks at that depth behaved in unusual ways. The unexpectedly high temperatures coupled with the greater porosity and decrease in density made the rocks appear pliable in nature.
The rocks adopted a behavior much like plastic rendering the conditions near-impossible to continue the drilling process. It forced the Kola team to abandon the project in 1992 completely. It had been 22 years since the team started drilling the site, but all was not lost.
Unearthing Long-Lost Relics
Before sealing up the site, researchers gathered a wealth of knowledge from the well, which we now know as the Kola Superdeep Borehole. Four miles into the ground, they found the presence of marine plants and tiny fossils.
The relics were also in a surprisingly intact state despite being buried underneath miles of rock for what has been estimated as about 2.7 billion years old. In total, they unearthed 24 single-celled organisms that were long thought to have been wiped from the planet. The marvelous subterranean surface also surprised us in terms of the shift between the underlying igneous rocks.
Igneous Rock Shifts
The further down the Kola Superdeep Borehole sank, the more exciting discoveries it presented. Experts had previously deduced from seismic wave readings that the ground beneath transitions to basalt from graphite at the two to four-mile mark. The Kola Peninsula disproved this theory.
To revisit science class a bit, granite is the coarse-grained rock found on our planet's continental crust. It forms from semi-molten or molten natural material (magma), and it contains high contents of silica. Basalt is a silicate rock that forms when iron and magnesium-rich lava rapidly cools.
No Presence Of Basalt
The researchers only came across granite, even at the borehole's deepest point. Seismic activity previously suggested that at such depths, basalt superseded granite. However, what they observed debunked the theory that basalt occurred as a result of metamorphosed granite.
They eventually concluded that the shift in seismic waves came about from metamorphic differences within the rock. It also supported plate tectonics, which advanced the idea that the Earth's outer shell has several plates gliding over the mantle, and it was a new concept at the time. Even more amazing, they came across flowing water where nobody thought it existed.
Proof Of Biblical Floods
Almost throughout the drill path, researchers found mineralized water. Granite is considered a dry rock, and the water went as far as 7.4 miles into the crust. Some enthusiasts suggested that discovering subterranean water at such depths proved a biblical story.
They suggested that the water could be remnants from the iconic floods that wiped out most life on our planet. Science shows that the phenomenon is the result of hydrogen and oxygen atoms being forced out of the crust's rock by strong pressure. The impermeable rocks that formed overhead then trapped the newly formed water where we never thought it existed.
Permanently Closed
When the Kola Superdeep Borehole closed shop, it coincided with the Soviet Union's collapse. By 1995 the site was permanently closed down, and it was no longer open to visitors. However, the nearby town of Zapolyarny still welcomes those who wish to set their eyes on some of the project's relics.
The Kola Borehole now has a metal lid wielded over the nine-inch-wide opening preventing anyone from plummeting down the 7.5-mile hole. To put it into perspective, it would take between 3.5 to 4 minutes for any unlucky person who fell inside the borehole to reach the bottom.
Going Underneath The Seafloor
The subterranean quest didn't stop there, and several more projects over the years have attempted to get as close to the mantle as possible. The International Ocean Discovery Program (IODP), which focuses on advancing marine research, continues with the earth science projects.
The IODP naturally works in the deepest trenches of the sea, battling the extreme conditions within the element to uncover the secrets that affect several aspects of our planet. The data they've collected from ocean drilling projects has improved the scientific understanding of aspects like the origins of ancient life, the Earth's tectonic plates' processes and structure, climate change, and the uppermost mantle.
Exploring The Waves
The plunges into the Earth's water bodies are not always motivated by the need to reach the planet's center. For instance, a discovery mission launched in the Antarctic saw a two-man submersible dropped into the cold waters. The aim was to get near the South Pole waves and, in essence, go further than any other human-led expedition had reached.
The data collected from that mission equally taught us more about our planet than we have previously known. Marine biologist Dr. Jon Copley took part in the expedition that was aired as part of BBC's Blue Planet II series.
A Journey Back To 350 Million Years Ago
The dive culminated from a two-year research process because reaching the arctic floor successfully required the perfect timing. Copley explained that taking the deep sea dive into the Antarctic felt like hopping on a time machine and going 350 million years back. The depths of the Antarctic ocean floor still have "white spaces'' that are far-placed from the reach of scuba divers.
These areas are only partially mapped by ships' sonar, and they have rarely been explored by either remotely occupied or human-occupied ocean vehicles. Dr. Copley explained that they didn't go through the hardships early polar land explorers endured, but the dives allowed them to experience unique science.
Special Depths
The depths of the Antarctic ocean are special for several reasons. To begin with, ice sheets weigh down the region making the submerged continental shelf deeper than usual. The edge of the shelf is about 1600 to 2000 feet in depth compared to the 300 to 600 feet where other similar water bodies hover.
Inshore, even deeper channels are found, and some plunge down more than half a mile deep. Large ice sheets scoured them out in the past, and although the continent is remote, these areas are now accessible through submarines. Dodging icebergs was one of the challenges Dr. Copley's team faced while in their minisubmarines.
Finding The Perfect Location
According to Dr. Copley, the ocean around Antarctica functions like lungs in the deep. The majority of life-giving oxygen contained in the world's deep waters begin their journey from the Antarctic atmosphere. When the continent's seawater freezes in winter, air creates a reaction where the salty and cold water sinks. It then flows to the Pacific, Atlantic, and Indian Oceans.
Location was key for this expedition, factoring the narrow window of ice, wind, and sea conditions that supported the descent. They settled for "Iceberg Alley," a location that earned the name for good reason.
Navigating Through The Antarctic Peninsula
The chosen alley convenes a channel located near one of the northernmost points of the Antarctic Peninsula. It describes a stretch of sea with chunks of shifting ice surrounding it, and some of these pieces are similar to the size of a standard motor vehicle. Others stretch out for half a square mile.
It means that navigating a boat ferrying a submersible through them proves a challenge. That doesn't even touch on the process of lowering the submersible itself down the waters, and in turn, having the human-driven vessel plunge down to the deepest points.
Real-Life Space Invaders
James Honeyborne, the executive producer of BBC's "Blue Planet" series, explained that the team encountered obstacles on the way, and making it through Iceberg Alley was by far their greatest challenge. He likened it to a real-life version of the Space Invaders game.
The problem didn't end at navigating through the alley to the correct position, and the team had to battle other elements. It's the reason why the process itself took a month, and the researchers faced a 3,280-foot drop underwater, relying on the bottom of an iceberg to make their way down to the seafloor.
Amazing Deep Water Discoveries
The team also couldn't predict how their submarines would perform under the deepwater strain. Those concerns soon faded when they started the descent, and it was all because of the breathtaking beauty they were treated to as they plunged into the waters.
They observed an ecosystem consisting of an incredible number of strange but yet amazing creatures. Some of the deep-sea animals had evolved, while others were never-before-seen sea creatures discovered during the expedition. One, in particular, got a name inspired by a key component from the Star Wars series of films.
Bizarrely Unique Creatures
Life above the waters of the Antarctic is unforgiving and harsh. It's the reason why most plants and animals in the region have special adaptations enabling them to endure the extremities. Likewise, beneath, an abundance of "otherworldly" sea animals converge, also have adapted to the unusually cold waters of the Antarctic.
Mark Taylor, who was part of the dive team, told LADbible that they saw more life within a square yard of the Antarctic waters than they had seen in the Barrier Reef of Australia. The reason is also because of the special conditions experienced in the area.
A Shower Of Deepwater "Snow"
Marine snow refers to the shower of organic material that is often seen falling to the ocean's depths from the upper waters. It comes from the surface animals and plants natural decaying process, just like dead leaves fall from trees to the forest floor.
Marine snow also includes various kinds of inorganic dust, sand, soot, and fecal matter. Dr. Copley explained that the marine snow they encountered in the region was "thicker" than had been seen elsewhere. It all went into supporting the unique ecosystems that thrive beneath the Antarctic waters.
Feeding The Bottom Of The Ocean
Marine snow serves as food for the deep-sea scavengers. The National Oceanic and Atmospheric Administration (NOAA) scientists found that marine snow contains plenty of nitrogen and carbon. The sea animals, in turn, derive energy and nutrients by feeding on the matter that typically comes from sunlit parts of the ocean.
The small percentage of marine snow that isn't consumed by the animals is incorporated into the muddy "ooze" that blankets the ocean floor, where they undergo further decomposition. Nearly three-quarters of the ocean floor is covered by the thick, smooth ooze collected every million years.
Fertilizing The Ocean
Krill poo also serves as yet another crucial food source in the deep. The small shrimp-like creatures are best-known for feeding whales, but they also play an important role in supporting the atmosphere and ocean's health.
The tiny creatures fertilize oceans and ultimately also support marine life through their fecal matter. Their excrements help to enhance the muddy ooze that makes up the bottom of the ocean. It creates the perfect habitat for life. However, we are not just talking about regular marine life, but the strangest creatures we've seen yet.
The Antarctic Sunstar
Copley explained that some marine life hovers around the shallower depths of the Antarctic waters. The water temperature at such depths is usually similar to the cold temperature experienced in the deepest parts of other oceans worldwide. In the past, the ancestors of shallow-living deep-sea creatures spread out from the Antarctic across the deep oceans.
The Antarctic Sunstar is easily amongst the most bizarre creatures discovered by the team. The creature even got the nickname "Death Star," a Star Wars reference, with good reason. Scientifically called Labidiaster annulatus, it's relatives to the regular starfish.
50+ Limbs
The Death Star is different from the familiar five-armed starfish because it can have as many as 50 limbs. It uses its multiple limbs like fishing rods by holding them upward, off the seabed, waiting to snag passing krill.
Tiny pincers on the Death Star's skin are sensitive to touch and snap shut whenever anything brushes against them. The adaptation gives them an upper hand against other marine creatures they prey on by enhancing their predatory reach. It can also grow larger in size than your average dinner plate.
The Top Of The Antarctic Food Chain
Fish serve as the dominant predators in other oceans of the world, but in the Antarctic waters, the Death Star reigns supreme. The South Pole waters are extremely cold, and few fish can thrive in the area. In fact, the Death Star feeds on just about any right-sized creature, from krill to even fish that cross their path.
Invertebrates like the Antarctic Sunstar easily make it to the top of the food chain on this account. It's also how the Earth ran some 250 million years back, and according to Dr. Copley, invertebrates ruled the oceans in the past, and they still do in the Antarctic region.
Promochocrinus Kerguelensis ( The Antarctic Feather Star)
Dr. Copley added that observing the Antarctic seafloor from their minibus gave them a better understanding of "dropstones." These are vehicle-sized boulders that have fallen off passing icebergs to settle on the sea bed where they create "islands of rocky habitats."
They house filter-feeding species that would otherwise wouldn't "feel at home" on the soft muddy Antarctic seafloor. The team was able to spot the Promachocrinus kerguelensis, an Antarctic Feather Star species discovered during the 1972-76 Challenger expedition. It's the only feather star in the Antarctic that has 10 rays on each of its arms. It makes the creature appear more feathery compared to its counterparts.
Ice Dragonfish
The parade of strange creatures residing in the depths of the Antarctic Ocean was extensive, and the team also came across the ice dragonfish. Also called the Cryodraco antarcticus, the ice dragonfish has equally adapted in a fascinating way to the Antarctic conditions.
It has antifreeze proteins, which prevent its clear blood from icing up. It has clear blood because of the absence of hemoglobin, which is responsible for giving our blood its red hue. The fish absorbs enough oxygen directly from the cold waters to "fuel its blood," which, in turn, keeps it alive.
Understanding How Life Thrives In The Antarctic Ocean
Beyond the sea creatures, Dr. Copley and his team also gained a better understanding of how life thrives in the Antarctic Ocean. This is a crucial aspect of the conservation efforts currently employed around and within the South Pole.
For instance, they observed that the undersea terrain determines where dropstones settle. When they end up on steeper undersea slopes, they slide down and end up scraping off the presence of marine life in the area. However, if they settle at a gully, they can boost the local biodiversity.
Everyday Life In The Deep
The dives also allowed them to watch the sea creatures go about their daily lives within the Antarctic depths. They also collected specimens, using trawls from ships and nets, that have aided in studying these creatures.
The bigger picture is that it's all helping us make the connection between how we co-exist with the fragile environment and also how our actions affect the ecosystem and vice versa. Dr. Copley explained that it would help demystify the Antarctic white space so that it doesn't appear like such a blank.
There's No Inaccessible Part Of Our Blue Planet
The most accessible oceans and their depths remain a mystery. Dr. Copely told the BBC that he hopes their expedition helped in some way to change this fact. Their travel into the Antarctic Ocean for the first time proved that no area within our blue planet could be ruled inaccessible. Dr. Copley added that as long as we find the will to explore these spaces, then we can always make it happen.
Dr. Copley also recommends pursuing an interest in marine life through initiatives like the "Capturing Our Coast Project." The initiative brings together nationwide volunteers to survey shores and monitor changes in species distribution around the United Kingdom.
Stewards Of The Future
Dr. Copley finished off by sharing the sentiments about the profoundness of traversing an area that's hard to reach, beyond the scientific scope. He explained that they were exploring nature "in its purest sense." He added that if we all took part in the process of trying to understand our planet, then we all end up being part of the "stewardship" that guides us into the future.
The University of Southampton, where Dr. Copley serves as an Associate Professor, offers a free online course touching on exploring our oceans. The course covers the history of our oceans, the science behind them, and their relevance.