Power point of the unit 1 about the Earth and its representation

1. Unit 1
PLANET EARTH
AND ITS
REPRESENTATION

2. 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.

4. 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.

5. 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

6. 1. Planet earth
• Almost a perfect sphere, but slightly flattened at the
poles. GEOID - SPHEROID

7. The earth in the solar system

8. • 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!

9. 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.

11. 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.

12. To be able to study the Earth the
geographers have invented
parallels and meridians

13. 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

14. 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

15. REVOLUTION AND SEASONS

16. 3. PARALLELS, MERIDIANS AND
GEOGRAPHIC COORDINATES

18. 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)

19. 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)

20. If we measure the latitude and longitude of a place, we can find
its exact location.

21. 180º W 150º W 120º W 90ºW 0º60º W 30º W 180º E150º E120ºE90º E60º E30º 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

22. REVIEW:
MERIDIANS PARALLELS
Do they join in the
poles?
Are they parallel to the
Equator?
They range from:
Used to establish:
0º is called:

23. Representing the world
Try to make a sketch map from
the institute to your home

24. 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

25. 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?

26. We can…
Flatten a sphere: So we have a map projection.

27. 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

28. These are the main map « projections »
of the Earth.
Conical projection
Cylindrical Projection (proj. De
Mercator)Planar projection…

29. 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.

30. 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.

31. 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.

32. Do you want to see some more?
These are the result of complicated
mathematical equations ...

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

34. Mercator

35. Peters

36. There are also world maps which
can focus on:
Europe and Africa…

37. America…

38. Australia…

39. And what about historical
cartography?
Pomponius Mela, s. I a.C.

40. MAPAMUNDI 1459
Made for Enrique V, king of Portugal

41. Islamic map

43. Is there any new continent in this map?

44. 5.MAPS: Type of maps. Scale.

45. TYPES OF MAPS

46. TYPES OF MAPS

47. TO REMEMBER:
DO A DIAGRAM ABOUT TYPES OF MAPS.
Physical Thematic
Definition: Definition:
Such as: (list all studied)
-
-
-
-
-
Such as: (list all studied)
-
-
-
-
-

50. CAREFULL! REMEMBER THE DIFFERENCE BETWEEN:

51. 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

52. 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.

53. Numeric
scale

54. Graphic
scales

56. THE SMALLER THE
SCALE IS (=the larger
is the divisor),
THE LESS DETAILED
THE MAP IS

57. 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

59. 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.