1.  State the structure of Earth
 Label the worlds crustal plates
 Explain that convection current causes
plates to move

3.  Innermost part of the Earth.
 3450km.
 Consists mainly of iron and nickel
 Very high temperature of 4000 ◦C
Quiz: How will the high temperature
affect the crust?

4.  Middle layer.
 2900km thick
 Mostly solid with the upper most layers
consisting of molten rocks known as
magma.
Lava flow on
Hawaii. Lava is
the extrusive
equivalent of
magma.
Quiz: What is the difference between
magma and lava?

5. • Outermost layer of the Earth.
• 60km thick and floats on denser mantle.
• Broken up into pieces known as crustal plates.
•

7.  Continental plates are lighter and consist of
land masses.
 Oceanic plates are heavier as they consist of
large water masses.
Quiz: what happens when an oceanic
plate collides with a continental plate?

8. World's Crustal plates

9. Quiz: Explain how convection currents
affects plate movement.

10.  Extreme heat from the
interior of the Earth causes
the magma to be heated up,
expand and rises.
 This generates convection
currents.
Quiz: Name an example of convection
current that u can find in the kitchen

11.  As the convention currents reach the
crust above, they spread out carrying
the plates above with it. Plates are
dragged apart.
 As the magma cools, it gradually
sinks back down to be re-heated.
The process causes the plates to
move towards each other.

12. Objective
• Describe and explain the 3
types of plate movements
• Identify the landforms that are
formed

14. (1) Convergent plates movement-
Crustal plates move towards each
other
(2) Divergent plates movement –
Crustal plates moving away from
each other.
(3) Transform plate movement- plates
sliding past each other.

15. Scenario 1: continental plate + oceanic plate

16. Scenario 1: continental plate + oceanic plate
Quiz: Which plate is heavier? What
landform is created?

17. Scenario 1: continental plate + oceanic plate
Converging plate movement
 Convention currents within magma pulls two
plates together.
 The heavier oceanic plate get subducted
while the lighter continental plate floats on it.
 Subducted part of the plate melts under high
heat to form magma.
 Magma then rises above the Earth’s surface
to form volcanoes.

18. Scenario 2: continental plate + continental plate
Converging plate movement
Quiz: What is the landform created?

19. Scenario 2: continental plate + continental plate
Converging plate movement
 When convention currents within magma push two
crustal plates together, there is immense collision
force.
 Rocks between the plates are pushed upwards,
folded to form fold mountain.
 Eg: Himalayas mountains, Andes and Rocky.

20.  When the convention currents in magma pull 2
oceanic plates apart, a ridge may form at the
boundaries.
 Magma may rise up the cracks to from
volcanoes.

21. Quiz: What landforms are formed when 2
continental plates collide?

22. • A ridge is a
geological feature
Ridge
consisting of a
chain of mountains
or hills that form a
continuous
elevated crest for
some distance.
• Ridges are usually
termed hills or
mountains as well,
depending on
size.

23.  Occurs at conservative plate boundary
whereby the plates are not created nor
destroyed
 Plates slide past each other.
 Eg; San Francisco fault.

24. Summary
• Plates move because of convection currents
within the earths crust
• There are 3 types of plate movements
• Convergent, divergent and transform plate
movements

25. Lesson objectives
• Know where the pacific ring of fire is
located at
• Draw diagrams of the 3 types of plate
movement

26. crustal plate movements
Fold mountains and volcanoes

27. Pacific ring of fire
The Pacific Ring of Fire (or just The Ring of Fire) is an
area where a large number of earthquakes and volcanic
eruptions occur in the basin of the Pacific Ocean.
Quiz: Why are the similarities
between the locations of the
volcanoes?

29. and volcanoes
Fold mountains and volcanoes are formed along the plate
boundaries. Refer to text pg 75

30. plate movement

31. plate movement

32. plate movement

33. Objective
• Label the parts of the volcano
• Describe the 3 stages/types of
volcano

34. Row row row your boat
gently down the
stream
Quiz: What happens after a volcanic
eruption?

35.  Vulcanicity is the process by which the
molten materials are forced onto the Earth’s
surface.
 The molten rock found below the earth is
called magma. When magma flows onto the
earth, it becomes lava.
 Lava flows through the earths surface
through a single opening.
 Overtime, the layers of lava forms a
volcano.

36. cinder
Pipe
Layers of
lava

37. Structure of a volcano
• A volcano is an opening in
the earths crust from which
materials are ejected
• During an eruption, molten
rock or magma is ejected
onto the earths surface as
lava.
• Gases such as steam and
carbon dioxide may also be
released.

38.  Crater – opening at the top of a volcano where
lava, rock fragments, gases and ash are ejected.
 Lava – Molten rocks that have been erupted onto
the Earth’s surface.
 Pipe – Channel joining the magma chamber to
the top of the volcano which the magma flows
through.
 Vent- Opening in the Earth’s crust where magma
rises and are ejected out

39.  Magma chamber – An underground
cavity which contains molten rocks.
 Cone – This is built up by
successive layers of cooled and
solidified lava, mixed with ash and
rock fragments.

40. Quiz: Why are the volcanoes in different
shapes?

41. (1)Basic lava flow
•- more fluid and thin and the lava travels over a longer
distance before solidifying.
•- lava flow faster and spread widely
•- Gives rise to a more gentle-sloping volcano (shield
volcano).
(2) Acidic lava flow
• Lava is thicker and more viscous.
• Travels over a shorter distance and cools and
solidify faster.
• Gives rise to volcano with steeper slopes.

42. Other examples are Mt Mayon in the
Philippines; Mt Merapi in Java.

43.  One of the best examples of a dormant volcano is
Mauna Kea, one of the five volcanoes that make
up the Big Island of Hawaii.
 The peak of Mauna Kea is 4,207 meters above
sea level, but 10,203 meters above the base of the
floor of the Pacific Ocean.
 Geologists classify Mauna Kea in the post-shield
stage of volcanic evolution. It stopped being a
shield volcano about 200,000 years ago.
 Mauna Kea’s last eruption is thought to be 2460
BC.

45. (Different stages)
• (1) Active volcano – A volcano that is
currently erupting or is likely to erupt soon.
(frequently)
• (2) Dormant volcano – A volcano that is
presently inactive but may erupt in the
future(occasional)
• (3) Extinct volcano – A volcano that is dead
and not expected to erupt again.

46. Summary
• Label the 7 parts of the volcano
• Describe the 3 stages/types of
volcano: active, dormant, extinct

47.  Hot ash, gas and rocks are poisonous and
hazardous to air. Disruption to traffic.
 High temperature lava flow, volcanic
bombs, cinder and ash may kill people, bury
farmlands and houses and destroy
infrastructure.
 Volcanic eruption may trigger landslides
that kill livestock and bury houses and
people.
•

48.  Soil near volcanoes are rich and fertile which is
suitable for crops to be grown.
 Geothermal energy generated by the heat from
volcanoes is used to produce electricity for
development of industries.
 Source of precious stones and minerals like
diamonds, copper, zinc, gold and silver etc
provide mining jobs.
 Volcanic rocks provide materials for landscaping,
construction and road-building.


49.  A form of tourism revenue as many religions
and cultural rituals are conducted by people
living on the slopes of volcanoes.
 Beautiful landscapes of volcanoes serve as
a form of tourist attraction.
 Eg Bali and Java.
 This provides jobs and revenues to the
locals.