Why We Can't Truly Explore the Mariana Trench

Exploring the Mariana Trench is far more complex than reaching its bottom due to extreme pressure, limited technology, and environmental challenges.

Key Takeaways

Exploration of the Mariana Trench is limited by extreme pressure and technological constraints.
Current submarine technology allows only brief, localized visits rather than extensive exploration.
The trench’s vast size and complex terrain make full exploration a massive logistical challenge.
Safety concerns due to pressure make submarine design heavy and slow, limiting mobility.
Environmental factors like marine snow reduce visibility and complicate observation.

What the video covers

Reaching the bottom of the Mariana Trench is not equivalent to exploring it due to limited time and mobility.
Submarines drop like rocks and can only stay briefly at the bottom before returning to the surface.
The Mariana Trench is a vast, complex tectonic scar, much larger than commonly imagined.
Extreme water pressure at the bottom (16,000 PSI) requires submarines to have thick titanium spheres and buoyancy foam, making them heavy and slow.
The physics of pressure, weight, and battery capacity severely limit submarine maneuverability and exploration time.
A submarine hull breach would cause instant implosion and death, making safety paramount.
Visibility at the trench bottom is poor due to marine snow stirred up by the submarine, creating underwater dust storms.
Remote exploration is limited by the need for tethered cables, which are difficult to manage in deep ocean conditions.
Biological samples often degrade before reaching the surface, complicating scientific study.
Comprehensive exploration would require thousands of specialized submarines working for decades, which is currently unfeasible.

Chapters

Why can't submarines explore the Mariana Trench extensively?

Submarines must withstand extreme pressure, requiring heavy titanium spheres and buoyancy foam, which limits their mobility and battery life, allowing only brief visits to a small area.

What makes the Mariana Trench difficult to explore compared to other environments?

The trench is a massive, complex tectonic scar with vast size and terrain, combined with extreme water pressure and poor visibility due to marine snow, making comprehensive exploration a logistical nightmare.

What happens if a submarine hull is breached at the bottom of the Mariana Trench?

A microscopic fracture would cause an instant implosion due to 16,000 PSI pressure, compressing air inside the cabin to extreme temperatures and destroying the submarine in about one millisecond.

Full Transcript — Download SRT & Markdown

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Imagine this. Let's imagine you build the most advanced submarine in human history. You sink 11,000 m into pitch-black water, surviving pressure that would instantly crush a tank. You hit the absolute bottom of the Mariana Trench. You look out a tiny window, snap

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a few pictures of the dirt, and float back to the surface. And then you tell the world that you've explored the deepest place on Earth. Except you didn't. We love to treat the Mariana Trench like it's a place we've already

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conquered, but reaching the bottom of the ocean and exploring the bottom of the ocean are [music] two completely different things. Surviving the drop down is hard enough, but actually staying down there to find out what's hiding in the dark, we can't do it.

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When a submarine goes down to the Mariana Trench, it doesn't drive down there like a car on a ramp. It's not like we have some crazy fancy jet engine to push it down either. It literally just drops straight down like a rock. A

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really expensive, still very technologically advanced rock. It takes hours just to fall to the bottom. Once it finally hits the seafloor, it lands in one specific spot. The pilot looks out the window, maybe drives forward a few hundred feet, collects a rock or two,

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and then immediately has to drop its weights and floats straight back up to the surface before the life support runs out. To put this in human terms, imagine you wanted to explore the entire continent of Africa. But your method of

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exploring is flying a helicopter into the middle of the Sahara Desert at midnight. You land, open the door, scoop up a single handful of sand, and then immediately fly back home. And then you proudly announce to the world that you

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have successfully explored Africa. That's exactly what we're doing with the Mariana Trench. We're visiting a single microscopic pinpoint of a massive ecosystem for about 60 minutes and then we leave. Actually exploring a place means you need to move around. You have

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to drive around, map the terrain, follow animals, and observe an environment over weeks or months. And we simply cannot do that. Part of the reason we can't just drive around is because people fundamentally misunderstand what the Mariana Trench actually is. When you

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hear the word trench, you probably picture a narrow pipe or a deep sinkhole. But the Mariana Trench is actually a massive tectonic scar tearing across the floor of the Pacific Ocean.

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It's over 1,500 m long. It's 43 miles wide on average. To put that into perspective, the Grand Canyon is about 277 miles long and 18 miles wide. The Mariana Trench makes the Grand Canyon look like a literal pothole in a Walmart parking

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lot, which is honestly kind of insulting to the Grand Canyon, but it's true. It's an endless landscape of underwater mountains, deep valleys, and jagged tectonic ridges. Even if you had the perfect submarine, the sheer square footage of the trench makes

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comprehensive exploration a complete logistical nightmare. You need thousands of submarines working around the clock for decades just to look at every part of it. And obviously, we don't have thousands of submarines. We barely have a handful that can even survive the

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trip. The reason we have so few vehicles capable of making this trip is just because of one unforgiving law of physics. Water pressure. At the bottom of the Challenger Deep, the water pressure is over 16,000 pounds per square

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inch. This is over a thousand times the normal atmospheric pressure you feel at sea level. Having 16,000 PSI pressed against you from every conceivable angle is the equivalent of having dozens of fully loaded jumbo jets stacked directly on top of your chest, which as you might

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guess is slightly bad for your health. So to survive this, a submarine's crew cabin has to be built as a thick titanium sphere. A sphere is the only shape that distributes external pressure completely evenly. But thick titanium is

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incredibly heavy. And if your submarine is too heavy, you will just sink into the mud and never come back up. So to counteract the weight of the titanium, you have to pack the rest of the submarine with thousands of pounds of

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highly specialized buoyancy foam. And this makes it an even worse problem for exploration. Because your submarine is now mostly just heavy metal and bulky foam, it's incredibly large and incredibly inefficient. Moving a giant object horizontally through dense water

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requires a massive amount of energy, which means you need massive batteries. But batteries are also extremely heavy, which means you need more foam, which makes a sub bigger, which means you need even more batteries. It's an endless loop of physics that basically

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guarantees your submarine will be slow, clunky, and, well, unable to really go anywhere. And you really, really don't want to cut corners on that titanium sphere just to save a little bit of weight because the stakes down there are

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basically just life or death. And a small piece of debris punctures the International Space Station. It's obviously an emergency, but you have time. The air slowly leaks out, alarms go off, and astronauts can seal the door or put on a pressurized suit. In the

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Mariana Trench, there's no such thing as a slow leak. If a microscopic fracture forms in your titanium hull, or if the thick acrylic window develops a tiny flaw, the 16,000 PSI of water outside is going to force its way in. And it

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happens so fast that it actually acts like a piston in a diesel engine. The water violently compresses the air inside the cabin in a fraction of a millisecond. This instant compression [music] causes the air to undergo adiabatic heating, meaning the

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temperature inside the submarine would instantly flash to the temperature of the sun's surface. The air combusts, the hole collapses inward [music] and the entire submarine implodes. And this entire process happens in roughly 1 millisecond.

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For context, it takes a human nervous system about 100 milliseconds to register pain. Which means if the submarine fails, you literally cease to exist before your brain can even process that something went wrong. It's instant deletion. And look, I'm not saying I'd

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never get in a submarine, but yeah, no, I'm absolutely never getting in one of those. So, engineers overbuild these submarines to be as safe and heavy as physically possible. But surviving the drop is only half the battle because

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once you finally hit the bottom, you still have to actually see what's down there. Assuming your submarine is built correctly and you safely reach the bottom without vaporizing, you now face the next major problem. You look out the

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window, turn on your massive floodlights, and prepare to see what's actually down there. And what you see is absolutely nothing. You might expect the floor of the Mariana Trench to be made of cool, jagged rocks or solid stone,

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but instead it's just covered in a thick layer of biological sediment. This is called marine snow. For millions of years, dead plankton, fish species, crushed shells, and organic dust have been slowly drifting down from the surface and settling on the bottom of

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the trench. It forms a layer of loose mud that coats basically everything. The second your heavy submarine gets close to the bottom, the water displaced by your vehicle stirs this mud up. And the moment you turn on your thrusters to try

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and move forward, you instantly create a massive underwater dust storm. Because you're in a deep trench, there are basically no strong ocean currents to wash this dust away. It just hangs there in the water. This blinding cloud completely ruins your visibility, and it

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can take hours to finally settle back down. But remember, your life support and batteries only allow you to stay down there for an hour or two. So, you just spent millions of dollars to drop to the bottom of the ocean only to sit

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inside a brown cloud of ancient fish poop until it's time to go home. Money well spent. If putting humans in the trench is this dangerous and clunky, the obvious solution is to just us

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We use drones for everything else. So, we should just send down a remote operated vehicle or an ROV and pilot it from the safety of a ship on the surface. But physics ruins this idea, too. Radio waves, GPS signals, and Wi-Fi

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absolutely don't work underwater. Water absorbs electromagnetic waves almost instantly. You cannot pilot a drone 7 mi down with a wireless controller. To communicate wirelessly underwater, we have to use acoustic modems. We literally send sound pulses, pings [music] through the water to transmit

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data. But sound travels relatively slowly and the bandwidth is well basically zero. It's like trying to load a 4K YouTube video using dialup internet from 1995 except the router is 7 mi away and constantly disconnecting. You cannot send live video feeds or precise

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joystick movements using sound waves. The only way to get a live video feed from an ROV is to physically connect it to a surface ship with a fiber optic cable. But dragging a 7m long cable through the ocean is a nightmare. Ocean

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currents pull on the cable. The ship on the surface bobs up and down with the waves. And the sheer weight of 7 mi of wire is enough to snap it in half. And if your tethered RO is exploring a rocky

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ridge at the bottom of the trench and that cable gets snagged on a sharp rock, you're done. You can't send a rescue diver down to untangle it. You just have to cut the cord and wave goodbye to your

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$30 million robot. Hope you kept the receipt. At this point, a lot of people usually ask, "Why don't we just invent better materials? We have carbon fiber, Kevlar, and advanced alloys. Surely, this is just an engineering problem we

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haven't tried hard enough to solve yet, but we actually have tried, and the ocean always wins. Take carbon fiber for example. It's strong and it's light. It seems like the perfect material for a deep sea submarine. But carbon fiber is

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designed to handle tension like being pulled or stretched. It's just really, really bad at handling extreme compression. When you take a carbon fiber hole down to 16,000 PSI, the water squeezes it. When you bring it back up, it expands. Over time, this repeated

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squeezing and expanding causes the microscopic fibers and the epoxy binding them together to weaken and dilaminate.

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It builds up microscopic fatigue that you can't easily see. And eventually, it just snaps. So, you can't use light materials because they shatter under pressure. And you can't use thicker, heavier materials because they sink and never come back up. There's no magical

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material on Earth that's simultaneously light enough to float, strong enough to survive 1,000 atmospheres of pressure indefinitely, and cheap enough to mass-produce. But even if we completely ignore the landscape and focus purely on the animals, we still have a massive

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issue. When a submarine or a lander manages to actually catch a deep sea creature in a trap, bringing it to the surface usually destroys it. These animals have evolved over millions of years to survive at 16,000 PSI. Their

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entire cellular structure, their proteins and their cell membranes are held together by that exact pressure.

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They even have special chemicals in their tissues called piselites that present the water pressure from crushing their proteins. When you drag the animal up 7 mi through the water column, the pressure drops from 16,000 psi to just 14 psi at the surface. Without that

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extreme pressure holding them together, the animal cells literally begin to expand and break apart. Their proteins unfold. Their tissues basically just fall apart. By the time they actually reach the scientists on the boat, they don't look like fish anymore. We can't

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dissect them properly. We can't observe their behavior, and we can't keep them alive in an aquarium. We're essentially just left with blurry photos and a puddle of indefinite goo, which doesn't exactly make for a great museum exhibit.

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And the animals we do manage to get blurry photos of only represent a tiny fraction of what might actually be down there. Because submarines are loud, slow, and completely blind in the dark, they're terrible at actively hunting or

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following animals. The only reliable way scientists have found to see life in the trench is to attach a camera to a heavy metal frame, strap a dead fish to it as bait, drop it to the seafloor, and wait.

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This method works for seeing things, but it creates a fundamental bias in our understanding of the deep sea. Because we're using dead meat on a stick, we're only ever going to attract scavengers.

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We're only discovering the ocean's garbage disposals, the animals that make a living sniffing out rotting corpses that fall from the surface. Basically, the deep sea equivalent of raccoons. If there's a fast-moving apex predator living in the Mariana Trench, something

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that hunts live prey, relies on vibration, and actively avoids clunky metal objects, we'd literally never know it exists. It would never come anywhere near our bait traps. It's like trying to study the wildlife of North America by leaving a piece of roadkill in a parking

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lot, taking a picture of the vultures and raccoons that show up, and concluding that wolves and mountain lions must not exist. Since dropping in for a few hours is inefficient [music] and bringing things to the surface destroys them, you might think the

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obvious solution is to just stay down there. We built the International Space Station so astronauts could live in space for months at a time. Why not build a pressurized habitat at the bottom of the Mariana Trench? Scientists could live inside, look out the windows,

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and deploy small drones every day without having to travel 7 mi up and down. It sounds like a great sci-fi movie, but it's basically engineering suicide. Actually, no. It's just regular suicide. Space is a vacuum. The pressure inside the ISS is one atmosphere, and

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the pressure outside is zero. The walls of the space station only have to hold back a pressure difference of one atmosphere. The base at the bottom of the trench would have an internal pressure of one atmosphere and an

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external pressure of a thousand atmospheres. The base would be aggressively crushed by the weight of a continent 24 hours a day, 7 days a week.

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You'd have to figure out how to pump fresh oxygen down 7 mi of pipe without the pipe collapsing. You'd have to magically generate power in the pitch black and dock a submarine to the airlock without the 16,000 PSI water

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instantly blasting through the seal. And realistically, you just can't. The environment down there just really doesn't want us to stay. But honestly, even if we magically solve the physics, the pressure, the mud, and the communication issues, there's an even bigger problem stopping

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us from exploring the trench. And that's simply money. It costs hundreds of thousands, often millions of dollars, just to rent a specialized research ship for a few weeks. [music] You have to pay for the crew, the crane operators, the

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submarine maintenance, the fuel, and the scientists. And for what? When we spend billions of dollars exploring space, we get a massive return on investment.

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Space exploration gave us GPS, satellite television, global weather tracking, advanced military dominance, and the potential for asteroid mining. There's a massive financial incentive to go to space. The Mariana Trench gives us a new species of translucent worm. Woohoo!

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There's basically no money to be made at the bottom of the ocean. There's no sunlight. There are no easily accessible rare earth metals that wouldn't cost a trillion dollars to mine. And there's no strategic military advantage to hiding a

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submarine in a trench that would instantly crush it. Outside of a few passionate marine biologists and billionaires looking for a thrill, no government or major corporation is going to spend billions of dollars just to look at mud and worms. Now, obviously,

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this doesn't mean we have completely given up on the ocean. We aren't just sitting on the surface crying about the pressure. Since putting humans in the trench is too hard and tethered ROVs are too risky, scientists have started

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relying on AUVs. Autonomous underwater vehicles. These are basically underwater drones that kind of look like this. They don't have a tether and they don't have a human pilot. Scientists program them with a set of AI instructions on the

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surface, drop them in the water, and just hope they come back. These AUVs swim a few hundred feet above the trench floor safely out of the mud, and they constantly bounce sonar pings off the ground. They fly back and forth in a

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grid pattern for hours, recording how long it takes for the sound to bounce back, which allows them to build a highly accurate 3D topographical map of the trench. We definitely aren't getting cinematic footage out of a submarine window, and we aren't catching any weird

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fish, but it actually works. We're painstakingly mapping the physical shape of the deep ocean using sound, but having to map our own planet using blind sound waves just proves an uncomfortable proof about human exploration. Space is actually incredibly easy compared to the

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ocean. We have highresolution 4K maps of the entire surface of Mars. We have rovers driving around on another planet shooting lasers at rocks. We sent the Voyager probes so far out that they literally left the solar system. And we

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can still communicate with them across 15 billion miles of empty space. But we can't send a simple text message 7 mi underwater. Space is empty. It's a vacuum. It doesn't fight back. Once you get past the Earth's gravity, you can

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basically just coast. The ocean, on the other hand, is aggressively in the way. It actively tries to crush you. It blocks your light. It dissolves your equipment. And it swallows your radio signals. Water just physically ruins everything. As a species, we're

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incredibly used to getting our way. We have climbed the highest peaks, crossed the most brutal deserts, and literally walked on the moon. But the Mariana Trench is different. It's an environment that simply doesn't let us in. No matter

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how much money we throw at it, no matter how much ego we have, the laws of physics currently dictate that we're not allowed to freely roam the bottom of our own planet. We can only drop down, take a quick peek through a tiny 6-in glass

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window, and retreat back to the surface before the ocean decides to keep us there forever. It's a pretty humbling realization. We always assume the most inaccessible mysteries in the universe are millions of light years away in some distant galaxy, but sometimes they're

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right beneath us, hiding in the dark. But anyways, I'm personally perfectly fine just staying on the surface for now. Thank you guys for watching and I hope you enjoyed this one. Please leave some suggestions in the comments for

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future videos because I will actually read them. Also, if you haven't seen my second channel yet, Beyond the Green, make sure to check the link in the description. It's similar stuff, just safely out of the water. Way out of

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whatever's going on in this trench. Although, I do really think this trench is cool, even if I would never want to take a trip down. And if you want to see our video about the weird deep sea creatures we have actually managed to

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find, check out this video here.

Topics:Mariana Trenchdeep sea explorationsubmarine technologyocean pressuremarine snowdeep oceanChallenger Deepunderwater explorationoceanographyextreme environments

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