What If You Detonated a Nuclear Bomb In The Marianas Trench? (Science not Fantasy)


What would happen if we detonated humanity’s most powerful nuclear weapon at the deepest point of the ocean? For sure, tsunamis hundreds of meters high would destroy coastal cities, earthquakes would level countries, new volcanoes would bring us nuclear winter. Maybe even Earth could be ripped apart? Or thrown out of orbit? Well, almost. Currently, Earth’s deepest known point is inside the Mariana Trench. The Mariana Trench is a very deep valley right at the edge of two tectonic plates that looks like an upside-down mountain. It reaches a depth of about 11 kilometers, almost three times deeper than
the dark grave of the Titanic. It’s one of the last places on Earth for humans to explore. Pitch black and under a thousand atmospheres of pressure, it’s a relatively pristine environment thanks to the absence of humans. A great place for our nuclear test. We’ll use the most powerful nuclear bomb humans have ever exploded, the RDS-220 hydrogen bomb or Tsar Bomba. Its explosion was so massive that its shockwave traveled around the Earth three times, and its mushroom cloud stretched 56 kilometers into the sky. Its shockwave was strong enough to destroy everything in a thousand square kilometers, its fireball hot enough to burn the rubble. Bombs like this release such an enormous amount of energy at once, that they could boil away an entire lake. And if we set off a nuclear bomb in the Mariana Trench, that’s exactly what happens. Let’s pull the trigger. In the first few microseconds, the nuclear fuel undergoes its chain reaction and explodes with the power of 50 megatons of TNT. A blinding flash of light illuminates the darkness of the trench for the first time in history. The heat of the explosion produces a cavity, a flaming bubble of water vapor, radioactive nuclei, and the remains of very unlucky fish. The bubble grows quickly as it vaporizes the water around it. The pressure of the bubble is immense, plowing outwards as if there’s nothing in the way. Sending off a shockwave that will be felt by seismic stations and whales around the world. And then, almost as fast as it emerges, it stops. On the surface of the Earth, this fireball bubble would grow to ten kilometers the second after it’s detonated, as the atmosphere barely puts up a fight to hold it back. But the pressure at the bottom of
the Mariana Trench is enormous. With 11 kilometres of water overhead, being in the Mariana Trench is like being crushed by a hydraulic press from every direction. Here, a second after the detonation, our bubble is about a kilometer across, when oddly enough, it starts to shrink. The bubble overextends itself, losing pressure as it expands, until the water turns it back, recompressing it. The tug of war between the fiery death bubble and water goes back and forth a few times, the bubble shrinking and growing, until eventually the bubble loses for good. The pressure around it is too great, and turbulent water begins to chop it up. It becomes something like the underwater equivalent of a mushroom cloud as it disintegrates into many smaller, hot and radioactive bubbles drifting upwards. And as our mighty destructive blast rises to the surface, it does basically nothing. Just a small wave, and a bubbling plume of radioactive warm water in the Pacific. No tsunami will wash away Japan or California, although boats and whales in the area might have a bad time. The radioactive fallout will be diluted into the Pacific after a few days, although a fair amount of radioactive water and salt makes it to the atmosphere where it collects and then rains down again. Even if the wind blows the fallout directly towards the Philippines, the worst of it probably happens over the oceans. But clearly, the real danger comes from our explosion-triggering earthquakes and volcanoes, right? Even if we detonated the bomb right in the trench at the exact point where tectonic plates touch, probably not. The explosion would vaporize a part of the seafloor, and turn a lot of sand into glass, but most of the energy goes into the water, not seismic waves. Earthquakes are already quite common at tectonic plate boundaries. And earthquakes with as much seismic energy as our bomb happen a few times a year without triggering any sort of apocalypse. But maybe it will affect the Earth’s orbit. Since no mass is taken away or added to the Earth, our orbit is completely unaffected. Also, there have been well over a thousand nuclear tests in the last 70 years and that didn’t change our orbit, so why would this time be different? The strongest forces humanity can unleash are laughable compared to the forces of nature. The planet is too big. It doesn’t care. So, what happens to us if we detonate a nuclear weapon really deep in the ocean? Pretty much nothing. Did you know that every bird in our videos has an owner? More than 1,000 people have got their own bird. It helps us explain things, clowns around in the background, or dies a horrible and avoidable death. If you want your own bird too and you
want it to appear in one of our videos, you can get it at patreon.com/kurzgesagt. Patreon is one of the main ways we sustain ourselves. So on top of getting a super nice avatar, you also help us make more and better videos. [Quacking] [Outro music]

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Reader Comments

  1. abdulrahman chalya

    Theres a video of a guy who blew up a fore cracked at the bottom of a lake and many of the fish around died because their organs were ripped apart how many fish would die because of the shock wave?

  2. Samuel Dickinson

    You said yourself that a bubble of 1km diameter would form as the water would vaporize. Using a simple sphere equation we can work out that this is the rough equivalent of 4.2 cubic kilometers of water displaced. While this may not cause a catastrophic tsunami, the act of this force effectivley acting on the sea bed would almost certainly cause other earth quakes which could possibly trigger even larger tsunamis. While theses tsunamis may not be massive most natural tsunamis only happen 1 at a time and not all toghether and so it may be possible that due to defraction on coastlines that 2 or 3 of these tsunamis may collide at the right angle and time to produce a massive one which we could also not predict coming.

  3. JorgeAraujo97

    "The planet's too big, it doesn't care!", yet there's a religion-like cult following of loonies blaming humans for the so-called "global warming". Couldn't agree more with the planet's too big remark.

  4. Raz Oudmayer

    nuclear bomb in ocean does nothing! thats not true, it kills a LOT of sea life and make the area unhospitibal for any life whatsoever and only gives another example of how we dont care about our oceans by pollutuing them

  5. Sergeant Sniper

    So, you guys did a nuke in the deepest part of the ocean, and you also did every single nuke detonated at once. Now we have to answer this question:

    Every single nuke detonated in the Marianas Trench.

  6. Miko - Brawl Stars

    Want a bird? Next video: Your bird dies a horrible death in an experiment involving a thermonuclear bomb some dinosaurs and the moon

  7. Victoria Hamilton

    "It does basically nothing, just … radioactive water in the Pacific … Boats and whales in the area might have a bad time. Radioactive fallout will be diluted in the Pacific over a few days. Although the fair amount of radioactive water and salt will make it into atmosphere, where it collects and rains down again." What? Nothing?

  8. M Infante

    We never were in real danger during cold war. Politicians speak tough words but crazy rich people do not want to die. So no matter how crazy, the crazy will be stopped by crazy rich people. Defcon 1 is scifi as long as crazy rich stay crazy rich.

  9. Phased Spaces

    Another little nugget info that could have been added, is that for the few micro seconds that the Tsar bomba went through its detonation process, it released the equivalent energy of 2% of the output of the Sun .. Not bad for us tiny humans!?

  10. Beaky TheNoobie

    I would people need to disturb the mariana trench? Who know's, Maybe the'res ancient creatures down there that your going to extinct, And Humanity already had done enought harm to Earth.

  11. Arent Ibro

    how is it possible that in the depths of Mariana's trench an air bubble (1km) large will be created when the bomb explodes and nothing will happen on the surface !!! .. liquids do not compress!!!!????

  12. tim88435

    The Tzar Bomba was originally designed to be 100 mega tonnes, not the 50 that it was changed to to ‘reduce radioactivity’ due to fear
    Even if it were to be 100 mega tonnes, I don’t think it would change the result much…

    Edit: spelling

  13. Brolly5

    I have a great idea for a video.

    A million exploding suns. How much energy would that be? Take the largest known super nova ever, and times it's energy output by a million. What do you get?

  14. Noel Blake

    Clearly the scientific data doesn't support the claim everyone knows if u blow a nuke up down there Trump would be blamed for the earth being destroyed and they didn't factor in all the cows that fart and there gas would ignite and the ice will melt cold beer will no longer exist anymore either

  15. Anohail

    I have always thought this would be so. But I think the push/ pull spoken of would be more exciting. Should be more like cavitation bubble, collapse, slightly smaller cavitation, collapse and repeat… So more dead fish /really annoyed Wales added to downsides. (why do I think this?This idea comes from watching slomo guys filming gunshots under water and myth busters episode where the try to make a boat fly up out of the water with an explosion. Yes I think technically it's just a push pull, but come on multiple cavitations way more exciting.)

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