The document discusses the theory of continental drift proposed by Alfred Wegener in 1912. It explains that continents have been drifting for hundreds of millions of years, as evidenced by matching continental shapes and matching plant and animal fossils found around different continents. It describes Pangaea, the supercontinent that existed 300 million years ago before breaking apart. Tectonic plates and processes like erosion, transportation, and deposition shape the Earth's relief over time. External forces like temperature, water, wind and human activity also change relief through erosion, sedimentation, and the formation of features like canyons, deltas, cliffs, and sand dunes.

1. Unit 2
The Earth’s relief
Teacher Rocío González

2. 1- The Earth’s crust

3. Magma

4. Oceans and
continents

6. Activities
Exercises 2 on page 24,
3 and 5 on page 25 in your
notebooks.

7. 2- What is the Earth’s relief?

10. Ocean relief

11. Ocean relief

12. Activities
Exercises 1 to 4 on page 27.

13. 3- Internal forces of relief
Continental drift theory
Continental drift was a theory proposed in 1912 by Alfred
Wegener which postulated the movement of continents. This
theory is a part of the concept of plate tectonics. Continents
have been drifting for hundreds of millions of years.
Nowadays there exists lots of evidence for continental drift.
The most obvious is the way in which the continents seem to fit
jigsaw-like (for example Africa and South America) together
when looked at on a map. More scientific evidence comes in
the form of plant and animal fossils of the same age found
around different continent shores, suggesting that they were
once joined.

14. Pangaea
Pangaea (/pæn d iˈ ʒ ːə/)
was a supercontinent
that existed during the
late Paleozoic and
early Mesozoic eras,
forming about 300
million years ago. It
began to break apart
around 200 million
years ago. The single
global ocean which
surrounded Pangaea is
accordingly named
Panthalassa.

16. Tectonic plates
A theory that explains the global distribution of geological phenomena
such as seismicity, volcanism, continental drift, and mountain building
in terms of the formation, destruction, movement, and interaction of
the earth's lithospheric plates.

17. Faults and folds

18. What are volcanoes and earthquakes?

20. Geyser and hot springs

22. Earthquakes

23. ***Go to page 33 for a little advice!

27. Activities
Exercise 1 on page 28.
Exercises 2, 3 and 4 on page 29.
And finally, investigate! Exercise 5 on page 29,
and 11 on page 33.

28. 4- How does relief change?
CHANGES IN RELIEF
Relief is also shaped by external forces: temperature, water,
wind and human action. There are 3 processes:
EROSION: the wearing away of rocks and other deposits on the
earth's surface by the action of water, ice, wind, etc.
TRANSPORTATION: the eroded material is transported by water
or wind.
DEPOSITION: the material is deposited in areas where
sediments accumulate.

29. CAUSES OF EROSION

30. The course of a river

31. Canyons

32. SEDIMENTATION

33. Deltas

34. Cliffs

35. Sand dunes - wind effect

36. Temperature

37. Human action.
Reservoirs

38. Think about it. Terraces.
Inca terraces.

39. Think about it. Ski stations.

40. Think about it. Tunnels.

41. Think about it. Highways.

42. Activities
Exercises 1 to 4 on page 31.
Exercises 1, 4, 8, and 9 on pages 32-33.

43. Topographic profile
A topographic profile is a cross sectional view along a line
drawn through a portion of a topographic map. In other
words, if you could slice through a portion of the earth, pull
away one portion, and look at it from the side, the surface
would be a topographic profile.

45. Practice with topographic profiles
Exercises 1 and 2 on page 34.

46. Work with maps. Activities.
Exercises 1 to 5 on page 35.