Lesson video

Hello, my name is Ms. Gilyeat, and I'm going to be your geography teacher for today.

In today's lesson, we are going to be learning about map projections, which is the lesson in the what makes a geographer topic.

Let's get going.

So our lesson outcome for today is that you can describe how different map projections show the world.

We've got four keywords for today's lesson.

The first one is map projection, and this is the representation of an approximately spherical world as a flat map, necessarily involving distortion.

Two-dimensional, something that is flat.

Its dimensions are height, so top to bottom, and width, side to side.

Three-dimensional is something that is solid.

So its dimensions are height, top to bottom; width, side to side; and depth, front to back.

And topography is the study of the landforms and features of land surfaces.

Now, those four keywords will be highlighted in bold throughout the lesson.

So if you need to refer back to them at any point, you can do.

We've got two learning cycles.

So first of all, we are going to understand and learn about what we mean by a two-dimensional and a three-dimensional map.

And then we're going to learn about the different map projections of the world that there are and some of the positives and negatives of those.

So let's get going with our first learning cycle, finding out what two-dimensional and three-dimensional maps are.

Now, the best representation of Earth that geographers use is the globe.

Okay, so we've got a nice picture of a globe on the slide here.

Now, globes are three-dimensional.

On globes, the landmasses, that's the continents, are always drawn to their correct shape and relative size.

Now you might want to think, have you got a globe at home or have you ever used one? And if there's one in the classroom at the moment, it might be a good idea to pause the video and just hand the globe round to have a look at it.

Now, globes can show physical features, such as land and oceans, plus landscape features such as climate, vegetation, and topography, okay? So remember, topography is about the shape of the land.

Now if we have a look on my slide here, we can see that the different continents of the land masses are shaded in different colours.

Do you want to have a guess what you think the different colours represent? So we can see there that a desert has been coloured in yellow in Northern Africa, and you might recognise that as the Sahara Desert.

And then in South America there, the continent is being shaded in green, which is representing a rainforest.

So that's the Amazon Rainforest.

Globes can also show political features, such as the boundaries people have imposed in the formation of individual countries.

Okay, and these have actually changed over time.

So if we have a look at the picture on the slide, we can see that the different countries have been shaded in different colours to make that boundary clear where one country starts and another ends.

That's what you would class as a border.

Now, this is human geography.

Humans have decided where these lines will go.

They are not natural lines.

One country just isn't, you know, naturally there.

Humans have decided where one country starts and where one ends.

And things like walls and other kind of disagreements or agreements have changed where these political boundaries are over time.

Now, South Sudan is the newest country in the world.

It declared its independence from the rest of Sudan in 2011.

Let's check our understanding.

So globes are A, one-dimensional; B, two-dimensional; or three, oh, sorry, C, three-dimensional.

Globes are three-dimensional, or 3D for short.

Cartographers, and these are people who draw or design maps, have struggled how to produce a flat, two-dimensional, so 2D, map of Earth for many years.

So it's not a new kind of problem.

It's been going around for hundreds of years.

How do we create a 2D map of a 3D world? So why do you think it is so hard to show Earth as two-dimensional? Have a quick chat with your partner.

Now, it's hard to show Earth as a flat surface because our planet is not flat.

It's 3D.

Therefore, it's difficult to get an accurate picture of the size and the shape of the continents.

Earth is an imperfect sphere, so flattening it out into a rectangle is impossible.

All two-dimensional maps distort the shape and the size of land masses, okay, to some degree.

So we're going to look later in the lesson at some of the different examples of how cartographers have tried to do this, but all of them, they'll have some distortion to a degree.

So a way to kind of like get your head around this is imagine you had an orange and then you drew the continents onto the orange.

So it was spherical, a 3D globe.

And then if you were to peel that orange out, you wouldn't be able to get the orange peel into a complete rectangle shape.

Okay, so we've got a nice picture on the slide here which represents that.

World maps, which project the spherical world onto a flat surface, have been created in several ways, but nearly always with north at the top.

Let's check our understanding.

Two-dimensional maps are always accurate.

Is that true or false? That is false.

Now, can you tell me why? Flat maps distort the shape and the size of the landmasses.

Okay, we're on to our first task for the lesson, task A.

What I'd like you to do is answer these three questions.

Now, there's a worksheet to go with the lesson, or you could do them in your exercise book.

So question one, what is the difference between a two-dimensional and a three-dimensional map? Question two, what is a cartographer? And question three, can you explain why a globe is a better representation of Earth than a two-dimensional map? Pause the video and have a go at those three questions.

Okay, let's go through our answers.

So this, I've written a model answer here.

So these are kind of the things that you should have been talking about, but obviously you would not have need to have written this word to word.

A two-dimensional map is a flat representation of an area, whereas a three-dimensional map shows the height, width, and depth of an area.

A globe is a three-dimensional map.

So for question two, a cartographer is a person who draws or designs maps.

And for question three, a globe shows the continents in the correct shape and relative size.

A flat map distorts the shape and the size of continents and the countries within them.

So that's why a globe is a better representation of Earth.

Pause the video and check your answers.

Okay, let's get moving on to learning cycle two, which is looking at some of the different map projections of the world.

Now, cartographers has come up with different solutions of creating a 2D world map.

These are called map projections, and they are usually named after its inventor, so the cartographer that's decided to draw the map like that.

All projections of the world distort the shape of the land masses, and most distort the relative size.

So no 2D map is completely accurate.

Some world map projections retain parallel lines of latitude and draw lines of longitude parallel instead of converging at the Poles.

This distorts the projection of the land shape compare.

Sorry, this distorts the projection of the land shape.

So if we have a look at the slide here, we have got a picture of a 2D map on the left with a globe on the right.

Now I have highlighted in the white circle where Greenland is in both of the maps.

Now you can see there that it's the same continent, but they look very different.

On the left, Greenland looks much bigger and wider, whereas on the globe it's actually much more narrow and smaller.

So which is the more accurate representation? It is the one on the globe.

Okay, let's get going with our first map projection, which is the Mercator map.

So in the Mercator map projection, which was created in 1569, lines of latitude and longitude are straight.

Now, if you can't remember, so lines of latitude are horizontal lines which run across the Earth going from the equator.

And lines of longitude are long lines which go vertically down the Earth, okay? So we can use these lines, lines of latitude and longitude, to find out where places are in the world, okay? And you can do this by creating a bearing.

But this does distort the shape and the relative size of the land masses.

The Mercator map has been criticised as imperialist, okay? So that means that we're putting the UK as the central part of the map.

Well, not just the UK, Northern Europe countries as well.

So this projection overemphasises Northern Europe.

In the Eckert, the fourth projection, which was created in 1906, lines of latitude are unequal in their spacing and scale, resulting in the lines of longitude curving and converging towards the Poles.

So if you look here, the latitude lines aren't completely straight.

They've actually got a nice curvature to them, representing the curvature of the Earth.

So if we have a look, we can see at the top of the globe there, that's where the lines of longitude have converged at the top, at the North Pole.

Goode, which was created in 1923, devised a map with interruptions that minimises the distortion and resembles a flattened orange peel.

So Goode really wanted to try and get the size and the shape of the countries as close to a globe as he could.

But the only way that he could actually do this was to have sections missing from the map.

So it's as if literally if you had an orange peel, drew the continents on it the relative size and shape, and then you unpeeled the orange.

There would be sections which wouldn't have the drawings in it.

The Gall 1855 and Peters 1974 projections represent countries in their true proportion to one another.

An equal-area projection shows continents, countries, and oceans according to their actual size, and therefore comparison is possible.

So if we have a look at the map on the right, which is the Peters projection, you can see there that some of the countries do look a bit in a funny shape, but they are all the correct relative size to each other.

Now, looking at that, I actually think that Africa looks bigger than I thought it did, but that's actually the true size of it relative to other countries and continents of the world.

Okay, so Peter or the Peters projection does get the actual size correct.

So, however, even though he's got the size of the continents and the land masses correct, it does unfortunately distort the shape.

So as it says here, the Peters projection distorts the shape of the continents.

Landmasses look stretched at the equator, whereas at the Poles, they look relatively squashed.

This map doesn't accurately represent distance, so therefore it would not be used for navigational purposes because yeah, it would not be good if you use that because the distances are wrong.

Okay, let's check our understanding.

So which of these following maps is the Mercator map projection? Is it A, B, or C? The answer is B.

That's the Mercator.

World maps used by pupils in the UK have been called Eurocentric, okay? This basically means that the UK and Europe are placed centrally on the map.

Now, this is how the most world maps are, okay? However, that doesn't necessarily mean it's a good thing and sometimes it is good to question these things, even if that's what you are used to.

Some argue that this represents Europe with superiority, okay? Because we are constantly placing Europe and the UK in the middle of the map.

What do you think? Do you agree? Okay, we're on to our final task for this lesson.

So for task B, question one, you need to name the different map projections, A, B, C, and D.

Pause the video and have a go.

And for question two, I want you to rank the projections from which you think is the best projection of the world and which you think is the worst.

Then for question three, you are going to explain your ranking.

So what did you put at the top, so which you thought was the best projection.

And which do you think was the worst one? And you need to explain your reasoning.

There is absolutely no right or wrong for this question.

It's your own opinion.

So which do you think is the best and why? And which do you think is the worst and why? So pause the video and have a go at that question.

Okay, let's go through the answers.

So for the different map projections, A was the Mercator projection, B was the Eckert projection, C was the Goode projection, and D was the Peters projection.

Did you get those right? Well done if you did.

Okay, now I've put my rankings here, but absolutely, you did not have to agree with me, whatever you thought was the best.

So I've put the Peters at the top, followed by the Eckert, the Mercator, and the Goode projection as the worst, okay? But if you've put them in a different ranking, that's absolutely fine.

I will explain my ranking to you though.

So I think that the best map projection is the Peters projection because the size of the countries are all relative to each other.

This means that you can compare sizes of different countries.

I think that the worst map projection is the Goode projection.

This is because it's not the shape of a rectangle, so it's difficult to understand.

If you've put something different for your answers, that's absolutely fine, but maybe pause the video and have a think about what you've put.

Okay, we have got a summary for today's lesson.

So the representation of Earth on a globe shows land masses in the correct shape and relative size.

World maps project the spherical world, or three dimensions, onto a flat surface, two dimensions.

Some projections distort shape, others distort latitude and/or longitude.

There are criticisms on the orientation of world maps, claiming that many are Eurocentric.

Now that's it for today's lesson.

So well done.

You've done a fantastic job.

And that's all of it from me.

So yeah, I'll see you next time.

Bye.