Name: What Causes Earthquakes?
Uploaded: 2021-05-10T04:35:00.000Z
Duration: 3 min 46 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

The world around you is just full of things that are on the move.

Airplanes in the sky, cars on the road and tons of animals -- including you and me! -- are

It turns out that the ground beneath your feet is moving too!

Because, most of the time, the ground is moving very slowly.

But when you do feel the ground move, that's called an earthquake.

During an earthquake, the ground shakes—sometimes a little, and sometimes a lot.

It might seem kind of strange that the ground, which holds up houses and skyscrapers and

But it does—and it's all because of the way the Earth is made.

If you could cut the Earth in half, and look at it like this, you'd see that the Earth

The top, or outside layer of the Earth...what we think of as the ground...is called the

Now, even though the crust of the Earth is certainly very strong—it's not made of

The Earth's crust is actually made of many big pieces that fit together.

You can think of these pieces as being like the pieces of a giant jigsaw puzzle.

And we call these pieces of the crust plates.

Now, the edges of these plates aren't smooth along their edges, like the edges of the plates

These plates are made of very thick layers of rock—so their edges are bumpy and ragged,

And it's these plates that make up the Earth's crust that are always moving.

Like I said earlier, you usually can't feel or see them moving, because they move very,

Most plates just creep along at about one or two centimeters a year.

That's slower than your fingernails grow!

But how do these moving plates cause earthquakes?

Well, if you look at pieces of a puzzle, you'll see there there's a gap between the pieces

And, there's a line where the plates touch, too.

Some faults are very thin, and too small to be seen.

And some are very deep in the Earth's crust.

But some faults are really big, and you can see them right on the Earth's surface.

For example, this fault, which runs almost the whole length of the state of California,

And faults are where most earthquakes happen.

As the plates of the Earth's crust move past each other at a fault, the pieces of

rock that stick out of their sides sometimes bump into one another.

And when this happens, the ground above the plates—and anything on the ground—shakes.

But, sometimes the plates do more than just bump into each other.

Have you ever tried to open a door that's stuck?

You push and push...and then, all of a sudden...it opens really fast and bangs against the wall!

Well, sometimes, two different plates can't move past each other...and they get stuck.

They push against each other, just like you pushing against that stuck door!

When two things push against each other, the force of all of that pushing causes what we

And if the thing that's being pushed doesn't move, that pressure has nowhere to go.

In the case of our plates of crust, the pressure builds up where they're stuck.

It builds and builds...until the rocks break...and the plates suddenly move.

This causes the ground above the plates to shake … sometimes a lot.

How much the ground shakes depends on how much pressure has built up between the plates.

The more pressure...the bigger the earthquake.

So there's a lot of cool stuff happening beneath your feet!

Even if -- most of the time -- you can't even feel it!

We love viewer questions...so if you have a question about something you see, ask a

grownup to help you leave a comment down below, or send us an e-mail to kids@scishow.com!

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What Causes Earthquakes?

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