Lesson video

Hi everyone, I'm Miss Reid, and welcome to our final lesson on mountains, volcanoes and earthquakes.

Let's have a look at our lesson question.

So our question for today is how can we protect against earthquakes? Well, in this lesson, we're going to be learning about measures that cities have taken to protect their people and their city's infrastructure against earthquakes.

In this lesson, you'll need an exercise book or a piece of paper, a pencil, and your brain.

Please take a moment now to clear away any distractions, including turning off any notifications or apps or conversations that you have running in the background if you know how to.

Finally, if you can, try to find a quiet place where you won't be disturbed during the lesson.

Pause the video now so you can get the things you need and try and find a quiet place for this lesson.

Great, now you have everything you need, let's continue.

So we are geographers.

Geographers are types of scientists who study the earth, and this includes the land, the physical features and the people who live within it, and that's the human features.

In this lesson we'll be considering why is it important to put harm-reduction measures in place? How can old buildings be reinforced? What do new earthquake-proof buildings look like? So why is it important to put harm-reduction measures in place? Well, we'll learn a little bit more about what harm-reduction measures means in a moment, but what's important to know first is that between 1994 and 2013, nearly half a million people around the world died due to earthquakes.

How many people died due to earthquakes? Shout out a little bit louder.

That's right.

Nearly half a million people died due to earthquakes, with another 118.

3 million affected due to the loss of their homes and damage of infrastructure.

A further 250,000 deaths resulted from subsequent tsunamis.

So between 1994 and 2013, how many people died from earthquakes? Was it A, a quarter of a million people.

B, half a million people.

C, three quarters of a million people.

Or D, one million people? Pause the video now and choose the answer that you think is correct.

Let's take a look at the answer.

The answer was half a million people.

Pause the video now, so you can tick or fix your answer.

Great work everyone, let's move on.

So as this map shows us, earthquakes affect every continent, though certain areas are more prone.

Let's have a look at the areas that are more prone.

So you can see that along the Pacific border of North and South America, there have been a lot of earthquakes.

Throughout Southern Europe and lots of Asia and throughout New Zealand.

So there are certain areas in the world that are more prone to earthquakes.

Now this can cause devastating damage to the areas and large numbers of casualties.

And the more earthquakes that happen, the more that country or area needs to be thinking about what they can do to protect their cities and their people.

Now, the thing that's important to know about earthquakes is that it's the collapsing buildings that cause the most casualties or deaths, not the earthquake itself.

And this is why preventative or harm-reduction measures can make a huge impact.

Now harm-reduction measures are measures that are put in place to protect people from harm.

Let's say that again together, harm-reduction measures are measures that are put in place to protect people from harm.

Good work.

Here's the question.

What are harm-reduction measures? You need to choose the answer that you think is correct.

Let's read them.

A, measures that are put in place to protect people from volcanoes.

B, measures that are put in place to increase harm.

C, measures that are put in place to protect people from harm.

D, measures that are put in place to protect people from earthquakes.

Pause the video now so you can choose the answer that you think is correct.

Let's have a look at the right answer.

So the correct answer was C.

Harm-reduction measures are measures that are put in place to protect people from harm.

Pause the video now so you can tick or fix your answer.

Excellent work, let's move on.

So how can old buildings be reinforced? This is really important when we think about the cities and towns all over the world that have old buildings that need to be protected from the impact earthquakes.

Well, reinforce means to strengthen or support an object or substance, especially with additional material.

Now, a popular means of reinforcing a building or an old building is to add a steel structure like the one that you can see in this picture.

The most common type is the eccentrically braced steel frame.

Bit of a mouthful, should we say it together.

Eccentrically braced steel frame.

Good work.

Also known as EBF.

Slightly easier.

Now, EBFs are stiff themselves, and so suit stiff concrete or un-reinforced masonry walls.

And you can see that concrete has been reinforced in this image with the steel frame.

Often they're added to the exterior or outside of a building as it's cheaper and easier than adding it to the interior or inside.

Although it does alter the structure's appearance.

It does make it slightly less attractive.

Answer the question.

Why are steel frames used as a harm-reduction measure? Steel frames are used as a harm-reduction measure, because.

That's the sentence that you can use.

And here are some key words, stiff, increased protection.

Pause the video now, so you can answer that question.

Great work for having a go.

Let's compare your answer to mine.

I said steel frames are used as a harm-reduction measure because they are stiff so add increased protection to the building.

Pause the video now so you can tick or fix your answer.

Great job everyone, let's move on.

Now we're asking what do new earthquake-proof buildings look like? So we're thinking now about what are architects or designers doing to try and combat earthquakes in the future? Well, some architects around the world are designing rocking buildings.

Amazing, I know.

To enable a building to rock, the columns of the building's frame are not anchored or routed to the building's foundation.

So you can see in this image, the foundation or base, the bottom, and the columns of the building's frame are not anchored so that they can rock from side to side.

This means that when an earthquake occurs and shaking strikes, the building rocks as the frame lifts off the foundation and it tilts.

However, the building does not actually leave the ground because there is a central weight that ensures the frame stays rooted to the base.

And you can see in this image, if we zoom in here, you can see the weight here.

This is very important because of course, if a building was able to detach itself, then it would simply fall over.

So the building simply rocks away from the base.

Here's a question.

Let's have a look at it.

Why are rocking buildings used as a harm-reduction measure? Rocking buildings are used as a harm-reduction measure, because.

Here's some key words, columns, foundations, frame lifts.

Pause the video now, so you can answer that question.

Great work everyone.

Let's compare your answer to mine.

I said, rocking buildings are used as a harm-reduction measure because the columns of the building are not attached to the building's foundations.

So the frame lifts, when the shaking starts.

Pause the video now, so you can tick or fix your answer.

Great work everyone.

I'm so proud of all the work you've done.

That brings us to the end of today's lesson and the end of this unit.

A really big well done on all the fantastic learning you've achieved today.

If you're able to, please take a picture of your work and ask your parent or carer to share it with a teacher or your teacher so that they can see all of the fantastic things you've learned today.

And if you'd like, ask your parent or carer to send a picture of your work to @OakNational on Twitter so I can see your lovely work too.

Don't forget to complete your end of lesson quiz.

Enjoy the rest of your learning for today.

Bye.