Lesson video

Hi.

My name is Mr. Loledge and I can't wait to get learning with you today.

We're gonna have a fantastic time in this geography lesson.

Today's lesson is called The Formation of Mountains, and that's from our unit, Mountains and Volcanoes.

What, where and why? Our learning is tricky today, but I'm here to help and we can learn together.

Let's get started, shall we? By the end of the lesson, you'll be able to use geographical vocabulary to describe and explain how mountains are formed.

The key words we will be using today are tectonic plates, converge and mountain.

Can you repeat those after me? Tectonic plates, converge and mountain, the huge pieces that Earth cross is broken into are known as tectonic plates.

Converge means two things move towards each other, such as when two tectonic plates come towards one another.

A mountain is a natural raised part of Earth's surface that is higher than a hill.

Our learning today is going to be split into two main parts.

The first part is understanding Earth structure.

In this section, we're going to look at the layers of the Earth.

The second section is how are mountains formed? In this section, we're gonna look at how the tectonic plates move to form mountains.

Let's begin with our first section.

Understanding Earth structure.

Earth is approximately 6,400 kilometres deep from the surface to the centre and has a distinct structure of different layers.

Some layers are solid, some are liquid, which we'll discuss in the next few slides.

There are different thickness and a compose of different elements.

The four layers are the crust, the mantle, the outer core and the inner core.

Let's start with the innermost layer of the Earth, shall we and work our way outwards.

The inner core is the centre of Earth and thought to be a solid ball of iron.

Temperatures at the inner core are approximately 5,500 degrees Celsius.

Wow, that's hot, isn't it? The inner core is also approximately 1,200 to 1,300 kilometres thick.

Our next layer is the outer core and the outer core is the layer that surrounds the inner core.

The outer core is a liquid composed of iron and nickel and has a similar temperature to the inner core.

The next layer is the mantle.

The mantle is the thickest layer of Earth is approximately 2,900 kilometres thick.

It is made up mostly of semi-molten lava as it has been melted and moved by Earth's core.

Temperature at the mantel of between 1000 and 3,700 degrees Celsius.

The outermost layer of Earth is where our continents and oceans are situated and is the layer which we live on.

That's right.

This layer is called the crust and it is the thinnest layer of Earth.

Okay, that brings us to our first check for understanding, which is the layer of Earth on which we live? Is it A, the inner core, B, the outer core, C, the mantle, or D, the crust? Pause the video now to see if you answered that question correctly.

Welcome back.

Did you answer D correctly? The layer of Earth on which we live on is called the crust.

Well done if you've got that question correct.

Okay, we've got another check for understanding here.

Can you name the layers of the Earth? Remember, there are four.

Pause the video now to answer that question.

Welcome back.

Did you correctly manage to identify the crust, the mantle, the outer core, and lastly, the inner core? Well done if you've got all those correct.

Earth's crust is broken up into a series of enormous sections called tectonic plates.

Tectonic plates is one of our key words for today, so it's important that we remember that one.

This map shows the pieces of Earth's crust, the tectonic plates and where they are in relation to Earth's continent.

Remember, a continent is a huge mass of land, containing several countries.

As you can see, the tectonic plates fit together like a jigsaw.

The red lines on this map identify the boundaries of tectonic plates.

This is where two tectonic plates meet and is called a plate boundary or tectonic plate boundary.

There are seven major tectonic plates and many of the smaller ones.

The major tectonic plates by size are the Pacific plate, which is the largest plate, the North American plate, the Eurasian plate, the African plate, the Antarctic plate, the Indo-Australian plate, and the South American plate.

As you can see from this map, the United Kingdom is located on their Eurasian plate.

The tectonic plates are constantly moving as they sit on top of Earth's mantle.

Remember, Earth's mantle is made up of semi molten lava, which is constantly melting and moving, due to the heat from Earth's core.

Here we can see Earth's core melting the mantle, which in turn slowly moves the tectonic plates.

In fact, each tectonic plate moves on average, between one and 10 centimetres per year.

Okay, we've got another check for understanding here.

Can you explain to your partner how tectonic plates move? Try and think about the layers of the Earth, the mantle, tectonic plates.

We've got another check for him standing here.

Can you explain to your partner how tectonic plates move? Try to think about the layers of the Earth, especially Earth's mantle and how this causes the tectonic plates to move.

A bit of a hint here, you might want to include the word melting.

Pause the video now to see if you can explain to your partner how the tectonic plates move.

Welcome back.

Did you manage to correctly explain to your partner how tectonic plates move? One pupil has said that Earth's mantle moves as it is melting.

Tectonic plates sits on top of the mantle, so they move too.

He's right.

Well done if got that correct.

Let's keep going.

Tectonic plates can move in several different ways.

They can slide alongside each other.

They can move away from each other.

They can move towards each other or converge.

When plates move apart or diverge, the plate boundary is called a divergent plate boundary, when plate moves towards each other, the plate boundary is called a convergent plate boundary.

We're now onto our first task for today's lesson.

Can you use the diagram below to explain the directions in which tectonic plates move? Pause the video now to see if you can answer that question.

Welcome back.

Did you explain that tectonic plates can move side by side, away from one another or diverge and also towards one another or converge? Well done if you managed to answer those questions correctly.

We're now on to the second part of our lesson and that is how our mountains formed? Let's begin.

One way mountains can form is when tectonic plate converge, move towards each other.

Let's check our understanding on what we've just learned there.

Can you tick the statement which tells us how mountains are formed? Is it A, when tectonic plates move apart? B, when tectonic plates converge or move towards each other or C by weather? Pause the video now, see if you can answer that question.

Welcome back.

Did you answer B correctly? Mountains are formed when tectonic plates converge or move to towards each other.

Well done if you answered that question correctly.

There are three common types of mountains formed by tectonic plate movement.

These are fold mountains, fault-block mountains, and lastly, dome mountains.

We're going to look at these over the next few slides.

Fold mountains are often not very wide and have a pointy like top.

Mountain Everest which is the highest mount on Earth is one example of a fold mountain.

Fold mountains are the most common type of mountain.

When tectonic plates converge, which is when they move towards each other, the ground is pushed upwards, as we can see here, lifting and folding it and that creates mountains.

Fault-block mountains are often quite square cut and block-like.

The Santa Catalina Mountains in Arizona in the United States of America are fault-block mountains.

Let's have a quick look and see if we can identify how fault-block mountains are formed.

As the tectonic place converge or move towards each other, Earth's crust can break in place along lines of weakness.

These likes of lines of weakness are called fault lines.

When this happens, the crust can break into blocks, which you can see in the first diagram here.

The blocks are then pushed upwards to create fault block mountains and that's shown in diagrams two and three.

Our last common type of mountain is the dome mountain.

As the name suggests, dome mountains are dome-like and are rounded at the summit.

Half dome in Yosemite Valley, United States America is one example of a dome mountain.

Let's look at the formation of dome mountains.

Dome mountains are formed when molten rock or magma, pushes it away from the mantle into the crust.

As you can see here, the magma doesn't break the surface but forces the crust to bulge upwards.

It then cools and hardens to create a dome mountain.

Well done if you've listened really well there and learnt about our three common types of mountain and how they're formed.

I'm going to check your understanding now.

Can you identify the three common types of mountain? The options to choose from are A, fold mountain, B, table mountain, C, fault-block mountain and D, dome mountain.

Pause the video now and see you can identify the three common types of mountain.

Welcome back.

Our three common types of mountain are the fold mountain, the fault-block mountain, and lastly, the dome mountain.

Well done if you manage to get all of those correct.

Table mountain is not a common type of mountain.

We're onto our second task for today's learning.

Can you fill in the blanks using the keywords upwards, wind, Everest, folded, pointy and converge.

I'll read it out for you.

A fold mounting is formed when two tectonic plates move together or um.

The ground is pushed um, lifted and um.

Mount um is an example of a fold mountain.

Fold mountains are often not very um and are um on their summits.

Pause the video now and see if you see if you can fill in the missing words correctly.

Welcome back.

Does your work read like this? A fold mountain is formed when two tectonic plates move together or converge.

The ground is pushed upwards, lifted and folded.

Mount Everest is an example of a fold mountain.

Fold mountains are often not very wide and are pointy on their summit.

Well done if you managed to fill in all those blanks correctly.

That was a tricky task.

That takes us to the end of our lesson today.

Let's quickly summarise today's learning.

We have learned that Earth's crust is made from a series of tectonic plates, which constantly move, but so slowly that we don't notice.

Mountains are formed when tectonic plates converge, pushing the ground upwards, lifting and folding it.

Lastly, we've also learned that there are three common types of mountain, fold, fault-block and dome mountains.

Well done for all your hard work today.

You've been fantastic and I hope to see you again at some point soon for some more fantastic geography.