Name: The Ocean Is Deeper Than You Think. We Need Better Maps.
Uploaded: 2025-05-28T22:55:03.000Z
Duration: 13 min 22 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Adverbs of manner

But the maps that we have of our oceans are actually terrible.

Modal verbs - B1

If you look at Google Maps, you might think that we know the precise topography of all of this, but that's a lie.

We know less about the ocean floor than we do about the surface of Mars by a lot.

We have mapped Mars to a resolution of five meters per pixel.

For comparison, we've mapped the land on Earth to about 30 centimeters.

But most of our oceans, 1.5 kilometers, meaning 300 times less detail.

And that's a big problem because we're using the ocean all the time.

We're laying cables across it to carry your internet traffic.

And yet, we have a surprisingly limited view of what's below it.

Well, cartographically speaking, water sucks.

For Mars or Earth's surface, we can take pictures, but light doesn't get to the ocean floor, so we need other ways to see it.

And the good news is that we're developing that tech right now.

There is a terrifying, incredible alien world right there on our own planet.

And finally, we're using technology to see it more clearly.

In this video, we're going deep with some help from a friend to show you how we're mapping the ocean, the surprising things that we've found in the depths, and why this new technology could be huge, if true.

Map an ocean floor that nobody has ever mapped before.

Piece together a complete map of all the world's seabed.

And nobody really knows quite what's down there.

Mapping our oceans is shockingly hard, largely because they're just so much deeper than most people think.

Imagine that you walk off the coast into the water.

At 10 meters, or 33 feet deep, you're already experiencing an entire additional atmosphere of pressure on your body.

At 214 meters, you're passing the verified record for a human diver with no equipment, and it's quickly getting darker and colder.

At 828 meters, you're at the depth of the tallest building on Earth, the Burj Khalifa.

And 1,000 meters down, the world is unrecognizable.

No light from the surface can penetrate these depths.

The whole rest of the way is blackness, and you're less than 10% of the way down.

1,220 meters, you're in the territory of the deepest military submarines that we know about.

Just above it is where we think the infamous ocean gate submersible imploded.

The pressure down here, over 350 atmospheres, collapsed the faulty submersible in a thousandth of a second.

For reference, in space, it would take you up to 90 seconds to die.

So, I mean, if you ever have to choose between a few seconds in space or in the deep ocean, choose space.

Except, if you want to see aliens, choose the ocean.

The deepest recorded natural point is 10,935 meters, or 6.8 miles deep.

You might have heard of this spot, Challenger Deep.

If you put Mount Everest into the water upside down, there would still be over a mile until you get to the bottom.

It's roughly the average cruising altitude of a 737 airplane.

The ocean is incredibly deep and scary and amazing, which, as you can imagine, makes it very hard to map.

So we have over 70% of our Earth, most of which light can't penetrate and humans can't go.

I can see what looks like a topography of the entire ocean.

But if we haven't mapped the ocean in detail, what am I actually looking at?

We don't have good maps of the global seabed.

What quite a lot of those maps have been derived from is using satellite gravity data.

That's Steve Hall, marine scientist and ocean mapping expert.

He told me that because light can't penetrate past a certain distance, satellites use a method that totally blows my mind and has changed how I'm gonna look at the ocean forever.

The gravitational field of the Earth isn't absolutely constant.

So if there's a deep trench, there'll be ever such a slight dip down in the sea surface above it.

If there's a mountain, there'll be ever such a tiny bulge.

To create some of the topography that you see on Google Maps, we're using satellites to send radar pulses down to the surface of the Earth, measure the height of the water in different places, and then estimate the shape of the ocean floor.

The next time that you look out across the water, just take a second to appreciate how absolutely bananas this is.

But this radar on the ocean surface technique doesn't give us a very precise view of the seabed.

We still need to fill in a lot of detail.

You're looking at a pretty good approximation of what the shape of the seafloor is like.

And a lot of that has been put together by good quality, but educated guesswork.

For example, see these bumps and ridges right here?

We know that those are underwater mountains, but if you try and zoom in, it gets blurry.

There's just not enough data to make a clear image.

Luckily, we have other methods, some that were invented over 100 years ago.

In 1913, a German inventor created a device that could send acoustic waves into the water and record the time that it took for them to bounce back.

But it wasn't until the 1940s that a woman named Marie Tharp turned those sonar measurements into maps.

Those maps showed mountains and valleys and all kinds of things that we'd never seen before.

They were some of, if not the first, ocean floor maps ever created, but they've largely been forgotten by history.

I discovered that rare physical copies of them exist at the Library of Congress in Washington, D.C.

Now, I'm in New York, but I have a friend in D.C., and he loves maps.

I asked my friend and fellow video journalist,

Johnny Harris, to go find these old ocean maps so we could really see the progress that we've made.

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The Ocean Is Deeper Than You Think. We Need Better Maps.

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