Tectonic landforms: (A) Fold Mountains (B) Rift Valleys and Block Mountains (C) Types of Volcanoes (Shieldvolcano & Stratovolcano)

1. Living with
Tectonic Hazards
(Plate Tectonics)
Gateway 2

2. In this chapter, you will learn…
Gateway 1:
Why are some areas more prone to TECTONIC HAZARDS?
Gateway 2:
What LANDFORMS and associated tectonic PHENOMENA
are found at plate boundaries?
Gateway 3:
How do people PREPARE and RESPOND to earthquakes?

3. Gateway 2:
What LANDFORMS and associated tectonic PHENOMENA
are found at plate boundaries?
(A) Fold Mountains
(B) Rift Valleys & Block Mountains
(C) Volcanoes
Volcanic Eruptions
Earthquakes

4. Landforms at
Different Plate Boundaries
(A) Fold Mountains:
 Formation
 Locations

5. (A) Fold Mountains
Can you
guess how
fold mountains
are formed?
Clue:
usually found at
convergent plate
boundaries

6. (A) Fold Mountains

7. (A) Fold Mountains – Distribution
• Pg 22-23 shows location of fold mountains around the world
• Found at convergent plate boundaries (CC-CC & OC-CC)
• E.g. The Himalayas, The Rocky Mountains, Andes

8. (A) Fold Mountains vs Plate boundaries

9. (A) Fold Mountains
Rocky Fold
Mountain
Andes Fold
Mountain
(OC-CC
convergence)
Himalayas (CC-CC convergence)

10. (A) Fold Mountains
Andes Fold
Mountain
(OC-CC
convergence) Refer to Handout 5a / TB pg. 15

11. (A) Fold Mountains Himalayas (CC-CC convergence)
Refer to Handout 5a / TB pg. 14

12. (A) Fold Mountains - Formation
• Formed over millions of years
• Formation process:
• Continental crust(s) resist subduction as it is buoyant
and thick.
• Compressional force creates immense pressure
• Causes layers of rocks to buckle and fold upwards
• Process is known as folding

13. (A) Fold Mountains
Syncline
(downfold)
Anticline
(upfold)
Compressional
forces
Compressional
forces

14. (A) Fold Mountains
Anticline and Syncline: Southern California, USA

15. (A) Fold Mountains
Force of one side greater than the other:

16. (A) Fold Mountains
Guess who is younger?
Rocky Mountains (North America)
- Highest peak 14,440 feet (~4401m)
Appalachian Mountains (USA)
- Highest peak 6,684 feet (~2037m)
Less than 100 million years ago270-400million years ago

17. (A) Fold Mountains
Old vs young mountains:
Old fold mountains Young fold mountains
• Formed about 270-400
millions years ago
• Lower in height as they
were worn down by
weathering and erosion
• Formed less than 100
million years ago
• Can be as high as over 8 km
• Located along active plate
boundaries
• Still growing taller!

18. (A) Fold Mountains
Let’s watch! 
70 Million Years In 2
Minutes - The
Himalayas Forming
https://www.youtube.com
/watch?v=HuSHOQ6gv5Y

20. Landforms at
Different Plate Boundaries
(B) Rift Valleys & Block Mountains:
 Formation
 Locations

21. (B) Rift Valleys and Block Mountains

22. (B) Rift Valleys and Block Mountains
East African Rift
Valley System
(CC-CC
divergence)
Refer to Handout 5a /
TB pg. 12

23. Landforms at
Different Plate Boundaries
(C) Volcanoes:
 Internal structure
 Formation
 Types & categories
 Distribution

24. (C) Volcanoes
How many volcanic eruptions do you think
is happening RIGHT NOW??
https://www.volcanodiscovery.com/volcano-map.html
GUESS WORK

25. (C) Volcanoes
• Watch this! 
Geography Lesson: What is a Volcano?
https://www.youtube.com/watch?v=WgktM2luLok
• Label this! 

26. (C) Volcanoes
magma chamber
main vent
secondary cone
crater
lava flow
layers of lava and ash
ash & rock fragments
secondary vent
cone
An enlarged crater
is called a caldera

27. (C) Volcanoes
When asked to draw and label, please DO NOT give this…

28. (C) Volcanoes
THINK!
Do all volcanoes erupt
the SAME way?

29. (C) Volcanoes
Let’s watch  and compare:
1. https://www.youtube.com/watch?v=Be7o6BYVOzA
2. https://www.youtube.com/watch?v=nX2XHw-NB_w
Are they similar? Are there differences?

32. (C) Volcanoes
THINK!
Are all volcanoes of the
SAME shape and size???

33. (C) Volcanoes
Characteristics of lava:
• Silica content
• Viscosity - the stickiness of the lava / its resistance to flow
Type of lava: Basic Acidic
Temperature: High ~1,200°C Lower ~800°C
Silica content: Low High
Viscosity: Low
• Less sticky
• Flows easily
High
• More sticky
• Resistant to flow
Gases: Escape easily Traps gases
Eruption: Less explosive Explosive & violent

34. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
Type of lava: Basic
Temperature: High ~1,200°C
Silica content: Low
Viscosity: Low
• Less sticky
• Flows easily
Gases: Escape easily
Eruption: Less explosive
(a) Shield volcanoes:
• Gently sloping sides
• Broad submit
• Spreads out over large area
before solidifying
• When more eruptions happen,
base of volcano increases in
size as lava accumulates

35. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
Type of lava: Basic
Temperature: High ~1,200°C
Silica content: Low
Viscosity: Low
• Less sticky
• Flows easily
Gases: Escape easily
Eruption: Less explosive
(a) Shield volcanoes:
• E.g. Muana Kea – Hawaii
• E.g. Mount Washington - USA
• https://www.youtube.com/wat
ch?v=byJp5o49IF4

37. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(a) Shield volcanoes:
• E.g. Muana Kea – Hawaii

38. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(a) Shield volcanoes:
Successive layers of
solidified fluid lava and ash
crater
Thin, runny lava spreads
widely before cooling
secondary vent

39. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
Type of lava: Acidic
Temperature: Lower ~800°C
Silica content: High
Viscosity: High
• More sticky
• Resistant to
flow
Gases: Traps gases
Eruption: Explosive &
violent
(b) Stratovolcanoes:
• Develops from successive
eruptions of lava & pyroclasts
• PYROCLAST = ash + rock
fragments + volcanic bombs)
• Usually, violent eruptions

40. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(b) Stratovolcanoes:
• Lava from subsequent eruptions
covers the soft ash from initial
eruption & prevents it from being
eroded away.
• A high volcano with slightly
concave profile forms
• Steeper at the top
• Gentler at the base
Type of lava: Acidic
Temperature: Lower ~800°C
Silica content: High
Viscosity: High
• More sticky
• Resistant to
flow
Gases: Traps gases
Eruption: Explosive &
violent

41. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(b) Stratovolcanoes:
• E.g. Semeru stratovolcano –
Java, Indonesia

42. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(b) Stratovolcanoes:
Layers of lava & pyroclasts
(ash, rock fragments &
volcanic bombs)

43. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(b) Stratovolcanoes:
• PYROCLAST = ash + rock
fragments + volcanic bombs)
• Pyroclasts + super heated gases
= PYROCLASTIC FLOW
• Speed 200m/sec

44. (C) Volcanoes
Characteristics of lava  Different shape & size of volcano
(b) Stratovolcanoes:
• PYROCLAST = ash + rock
fragments + volcanic bombs)
• Pyroclasts + water from melted
ice/lakes in the mountains
= LAHAR
• i.e. fast flowing mudflows
• Speed 40m/sec
https://www.youtube.com/watch?v=kznwnpNTB6k

46. Compare & Contrast!
(b) Stratovolcanoes:
• E.g. Semeru stratovolcano
– Java, Indonesia
(a) Shield volcanoes:
• E.g. Muana Kea – Hawaii

47. (C) Volcanoes
Type of lava: Basic Acidic
Temperature: High ~1,200°C Lower ~800°C
Silica content: Low silica High silica
Viscosity: Low
• Less sticky
• Flows easily
High
• More sticky
• Resistant to flow
Gases: Escape easily Traps gases
Eruption: Less explosive Explosive & violent
Volcano formed: Shield Volcanoes Stratovolcanoes
Characteristics of lava  Different shape & size of volcano

48. (C) Volcanoes
Different shapes & sizes of volcanoes:
• Shape determined by…
- type of lava erupted
- the viscosity of lava
• Size determined by…
- the total volume of lava erupted

49. (C) Volcanoes
Distribution around the world:

50. (C) Volcanoes
Distribution around the world:

51. (C) Volcanoes
Distribution around the world:
• Most active volcanic activity occurs at the PACIFIC RING OF FIRE.
• Located at the edges of Pacific Ocean
(give examples of countries)
• Found along the boundaries of several converging plates
(give examples of plates)
• However, there are also volcanoes found at diverging plates such as
Atlantic Ocean and East Africa.
• Close correlation between the location of plate boundaries and the
distribution of major active volcanoes!!!!