The document discusses the Earth's relief and the forces that cause changes to it. It states that the Earth's crust is thicker in some places, forming continents, and thinner in others, forming ocean floors. The Earth's relief features such as mountains, valleys, basins and plains are not flat or smooth and are always changing due to internal forces from the Earth's mantle and external forces like water, wind, vegetation and human activity.

1. UNIT 3
THE EARTH RELIEF
THE OUTER LAYER OF THE EARTH

4. THE EARTH´S CRUST
• The Earth´s crust is thicker in some places, forming the
continents. In other places, where is thinner, it lies below
the oceans
• It is not flat and smooth
• On land and under the oceans there are mountains,
valleys, basin and plains. These features form the Earth
relief.
• Mount Everest is the highest point on Earth (8848 m.)
• The Mariana Trench is the lowest point (11022 m.
beneath the Pacific Ocean)

5. The Himalayan Range

7. Deepest Spot of the Planet

8. Internal and external forces cause the
earth´s relief which is always changing
Internal forces External forces
• The pressure from molten • Water
materials in the Earth´s • Wind
mantle can cause the crust • Vegatation
to crack. If this happens,
• Human action
large pieces of the crust can
rise above the surface, or
sink below it
• Volcanoes, earthquakes and
mountains are the result of
internal forces

9. QUIZ
1. What sections can the Earth be divided into?
2. Why are some parts of the Earth above the
water and other parts below it?
3. What internal and external forces change the
Earth´s relief

10. SOLUTIONS
1. The Earth is made up of three layers: the
internal core, thee external core, and thee
mantle and crust
2. In some areas the Earth´s crust is thik and it
forms continental land masses, and in others is
thinner and forms ocean floors
3. The internal forces that change the Earth´s relief
are the pressures from the molten materials in
the Earth´s mantle. The external forces are
water, wind, vegetation and human activity.