Unit 1 PLANET EARTH

AND ITS REPRESENTATION

Power point index: • 1.Planet earth

• 2. The earth movements

• 3. Parallels and meridians, and geographic

coordinates.

• 4. The representation of the Earth

• 5. Maps: Types and scale

• 6.Time zones.

QUESTIONS WE WILL ANSWER

Planet Earth in the universe: The earth in the Solar System and our solar

system in the universe. Shape and size of the Earth.

The Earth movements: rotation, revolution (definition, length,

consequences). What is a solstice? What is an equinox?

Geographic coordinates: Meridians and parallels. What are they? How

are the called? The hemispheres. How do we locate a point on Earth?

Latitude and longitude. Describe what latitude and longitude are. Search

the co-ordinates in a map. Find any point on a map with the help of

latitude and longitude. Give the latitude and longitude of any point on a

map.

The representation of the Earth. Map projections. Advantages and

disadvantages of the different representations. Types of maps:

topographic and thematic. Street map and plans.

How do we represent scale on a map? What do scales indicate? Types of

scales: numeric scale and graphic scale: explain them and calculate real

distances with a scale on different maps.

Time zones of the world.

USEFUL VOCABULARY FOR THE UNIT

• GEOID - SPHEROID

• ROTATION

• REVOLUTION

• CARDINAL POINTS

• COMPASS

• MERIDIANS

• PARALLELS

• HEMISPHERES

• EQUATOR

• LATITUDE

• LONGITUDE

• EQUINOXE

• SOLSTICE

• LEAP YEAR

• GRID REFERENCE

• SCALE

1. Planet earth

• Almost a perfect sphere, but slightly flattened at the poles. GEOID - SPHEROID

The earth in the solar system

• A STAR: Called the sun, which produces its own

light.

• PLANETS, which rotate on theis axes and revolve

around the Sun ando don’t produce their own

light.

• SATELLITES, which are smaller than planets and

rotate on their axes, and revolve around some

planets. The Earth satellite is the moon.

LEARN THE POSITION OF THE PLANETS IN THE SOLAR

SYSTEM FROM CLOSEST TO FURTHER!

Our solar system in the universe • The universe is made up of more than a hundred billion

galaxies. These galaxies come in many shapes. Our solar

system is located in a spiral galaxy called the Milky Way.

They are made of: planets, stars, gas clouds and cosmic

dust.

WHY DOES LIFE EXIST ON EARTH?

• DEPENDS ON 3 MAIN FACTORS:

1. The distance from the Sun appropriate

temperature. (Venus 457º or Uranus -220ºC)

2. The presence of abundant water

3. The existence of an atmosphere, a layer of

gases which surrounds the Earth and

protects life from dangerous solar radiation.

To be able to study the Earth the

geographers have invented

parallels and meridians

Is the Earth static? MOVEMENTS OF

THE EARTH

Rotation Revolution

It is the one which describes: the

Earth spins around its own axis,

anticlockwise direction.

It is the movement or the Earth

around the Sun

The axis of rotation is tilted with respect to the plane of the orbit that

describes the Earth around the sun.

As the Earth is spherical it

is only illuminated on the

face opposite to the sun.

As it is turning on itself, the

lighted face is not always

the same.

The seasons

365 days

and 6 hours

The seasons are determined

by the tilt of the earth's axis (areas receive more solar

radiation than others)

Equinoxes

Solstices

It is summer in a place when the sun´s rays

are almost perpendicular to it. It is winter

when the rays arrive at an oblique angle.

Spring and autum are the intermediate

seasons

!! When it is summer in the northern hemisphere, it is winter in the

southern hemisphere.

So the illuminated part (day)

and the dark part (night) are

constantly shifting.

The day, the night

A year

2. MOVEMENTS OF THE EARTH

2. THE EARTH MOVEMENTS

ROTATION

http://www.netanimations.net/24-hour-geostationary-

satellite-animation-loop-Earth.gif

http://www.netanimations.net/GPS-satellite-around-

Earth-moving-animation.gif

REVOLUTION AND SEASONS

3. PARALLELS, MERIDIANS AND

GEOGRAPHIC COORDINATES

LONGITUDE

Distance between any point on Earth and the Prime (or Greenwich) Meridian

Ranges between

0º-180º E and 0º-180º W

Because it’s an angular

distance it’s measured in

º (degrees) ‘ (minutes)

‘’ (seconds)

LATITUDE

Distance between any point on Earth and the Equator

Ranges between

0º-90º N 0º-90º S

Because it’s an angular

distance it’s measured in

º (degrees) ‘ (minutes)

‘’ (seconds)

If we measure the latitude and longitude of a place, we can find

its exact location.

180º W 150º W 120º W 90ºW 0º 60º W 30º W 180º E 150º E 120ºE 90º E 60º E 30º E

0º

75º N

60º N

45º N

30º N

15º N

15º S

30º S

45º S

60º S

75º S

0º

0º

75º N

60º N

45º N

30º N

15º N

15º S

30º S

45º S

60º S

75º S

90º N

90º S

90º N

90º S

REVIEW:

MERIDIANS PARALLELS

Do they join in the poles?

Are they parallel to the Equator?

They range from:

Used to establish:

0º is called:

Representing the world

Try to make a sketch map from

the institute to your home

The Earth is spherical Can you see the

continent Europe? Why?

?

In order to have a full view of all the continents, it is necessary to go around

the globe: This is a 3D representation!

Then ... How can the Earth be represented?

4. THE REPRESENTATION OF THE EARTH

We can…

Use a 3D image :

This is a globe, the Earth is represented accuretely .

However, globes do not contain detail information,

plus are not very practical to carry them around.

Would you use it to go to shool?

How can we have a full view of the Earth?

We can…

Flatten a sphere: So we have a map projection.

Ok, but...Have you ever tried to

flattten a sphere?

Impossible: it ends up being shorter down here ...

…than in there!

So, we can try to do it the other way around: transform a

rectangular sheet of paper onto a sphere

These are the main map « projections »

of the Earth.

Conical projection

Cylindrical Projection (proj. De

Mercator) Planar projection…

Cylindrical or Mercator Projection

CHARACTERISTICS, ADVANTAGES AND DISADVANTAGES:

-Meridians and parallels are cut to create right angles.

-Meridians are the same distance apart, but parallels are not.

-As the cylinder touches the globe at the equator, the representation of this

area is almost perfect, but there is a lot of distortion in the poles.

Conical projection (Lambert)

CHARACTERISTICS, ADVANTAGES AND DISADVANTAGES:

• Meridians are converted into straight lines starting at the poles.

• Parallels take the shape of arcs of concentric circles.

• As the cone touches the medium latitudes (between Tropics and Artic

Circle), the representation of this area is almost perfect, but there is

more distortion closer to the Equator.

Planar/Flat (Azimuth/Zenital) projection.

CHARACTERISTICS, ADVANTAGES AND DISADVANTAGES:

• A projection that maintains accurate directions from a given central

point is called an azimuthal or zenithal projection

• The globe is projected onto a circular flat projection.

• Meridians are converted into straight lines starting at the poles.

• Parallels take the shape of concentric circles.

• As the plane touches only one point of the Earth the representation is

the best for the polar regions.

• Preserves the correct distances from the centre point to the rest.

Do you want to see some more?

These are the result of complicated

mathematical equations ...

What differences can you see between these two types of projections?

Mercator

Peters

There are also world maps which

can focus on:

Europe and Africa…

America…

Australia…

And what about historical cartography?

Pomponius Mela, s. I a.C.

MAPAMUNDI 1459 Made for Enrique V, king of Portugal

Islamic map

Is there any new continent in this map?

5.MAPS: Type of maps. Scale.

TYPES OF MAPS

TYPES OF MAPS

TO REMEMBER:

DO A DIAGRAM ABOUT TYPES OF MAPS.

Physical Thematic

Definition: Definition:

Such as: (list all studied)

-

- -

- -

Such as: (list all studied)

-

-

- -

-

CAREFULL! REMEMBER THE DIFFERENCE BETWEEN:

THE SCALE The scale of a map is

defined as the proportion between

the real size of the

represented territory

and the corresponding

size on the map

1 cm on the map is equivalent to

16,000,000 cm (160 km) in the real

world

1 cm on the

map is

equivalent

to 1,300,000

cm (13 km)

in the real

world

Maps and plans represent large areas on small surfaces, so we need to know the relation between real size and the size shown on the map. SCALE: is the relation between the size of the area represented on the map and the real size of the area. It can be represented numerically and graphically.

Numeric scale

Graphic scales

THE SMALLER THE

SCALE IS (=the larger

is the divisor),

THE LESS DETAILED

THE MAP IS

GEOGRAPHY WORKSHOP CALCULATING DISTANCE WITH A SCALE

Scale: 1 cm = 50.000 cm What do I do next? I count cm from point A to point B 4 cm 4cm on the map are equivalent to 4 times 50.000 cm 4 x 50.000 cm= 200.000 cm But if we are talking about distance…better to do it in km. 200.000 cm are 2.000 m 2km Km Hm dm m dm cm mm 1000m 100m 10m 1m 0,1dm 0,01cm 0,001

6. TIME ZONES The Earth´s sphere is divided into 24 equal sections of 15º. These

sections are called time zones and each one equals one hour.