Learn about what happens during a earthquake by using this ppt

1. EARTH SCIENCE 8
S.Y. 2023-2024

2. GRADING SYSTEM
WRITTEN WORKS 40%
Quizzes, Long tests/Unit tests
PERFORMANCE TASKS 40%
Skill demonstration, Group presentation
Oral work, Multimedia presentations
Research projects, Written outputs
PERIODICAL TEST 20 %
____
100%

4. K E E F T A H Q L R U A

5. L E U F A T R

6. T B E S R K S A S

7. EARTHQUAKES
FAULTS
＆

8. WHAT IS AN EARTHQUAKE?
- is vibrations that
cause the breaking of rocks.
- is the shaking or
trembling caused by the
sudden release of energy.
These vibrations move in all
directions through the earth.
They begin at a point along a
fault.

9. …all about EARTHQUAKE!
Ground motion - A process that describes the movement of
the ground after an earthquake occurs
Seismology - study of an Earthquake
Seismologists - scientists who study Earthquakes.
- Philippine Institute of Volcanology and Seismology
- Agency that monitors the earthquakes and fault
movements.
PHIVOLCS

11. EARTHQUAKES AND FAULTS
PHILIPPINES – is located
along the ring of fire.
Ring of Fire – refers to the
region around the pacific
ocean that are commonly hit
by earthquakes and volcanic
eruptions.

12. WHAT CAUSES
EARTHQUAKE?

13. CONVECTION CURRENT
- Convection currents are the result of differential
heating
- Lighter (less dense), warm material rises while heavier
(more dense) cool material sinks.
- It is this movement that creates circulation patterns
known as convection currents.
COOL
WARM

15. STRESS IN EARTH’S CRUST
Stress is a force that squeezes rocks together,
stretches or pulls them apart, or pushes them in
different directions.
* As tectonic plate move, they cause stress in the crust,
which in turn produces faults and folds.

16. TYPES
OF
STRESS

17. Compression occurs when crustal rocks are squeezed
together.

18. Tension is the force that pulls rocks apart. Here rocks tend to
become thinner. Rocks under tension lengthen or break apart.

19. Shear is stress that occurs when forces are parallel but applied in
opposite directions.Sheared rocks bend, twist and break

20. WHAT DO YOU THINK WILL
HAPPEN TO ROCKS IN THE CRUST
WHEN PUT INTO STRESS?
IT BREAKS 

21. FOLDING…
When a rock has stress put on it and does not break it is called
folding.
Folds appear as wave-like structures in rock layers. Some folds
are small and can be seen in individual rocks and some folds are
huge and can only be seen from the air.

22. THREE TYPES OF FOLDS

23. Rocks don’t always bend, sometimes they break. When the rock
moves and breaks it is called a fault.

24. OBSERVE THE TWO PICTURES
Is there something in Figure 1 - A, B, C, & D - that
looks a like that formed in Figure 2?
Do you see anything similar to Figure 1 and
Figure 2?
WHAT IS IT?

25. WHAT IS A FAULT?
- a break in the Earth’s crust, and
along the break, significant
movement has taken place.
- The word “break” refers to a
crack in the ground.
- The word “crust” refers to the
outermost layer of the Earth.
- “Significant movement” means
that the rocks have been displaced or
shifted considerably.

26. WHAT IS A FAULT?
- A fault is a fracture or
series of fractures in
Earth’s crust that
occurs when stress is
applied too quickly or
stress is too great.

27. THE HANGING WALL and FOOT WALL
● The Hanging Wall is the one with the slope on which you could hang.
● The Foot Wall is the one with the slope on which you could walk.
● The type of fault is determined by the motion of the Hanging Wall.

28. THREE TYPES
OF FAULT

29. - forms as a result of tension.
- The rock layers in the Earth’s crust are pulled apart, and gravity
causes one section to move downward in relation to the other.
Normal Fault

30. - forms as a result of compression.
- The rock layers in the earth’s crust are squeezed together, and
the force pushes one section upward in relation to the other.
Reverse or Thrust Fault

31. - forms when the rock layers on opposite sides of a fault slides past each
other horizontally.
-This type of fault is sometimes called as tear, wrench or transcurrent fault.
Strike- Slip Fault

32. LEFT- LATERAL STRIKE SLIP FAULT
If you were to stand on
the fault and look along
its length, this is a type
of strike-slip fault where
the left block moves
toward you and the
right block moves away

33. RIGHT- LATERAL STRIKE SLIP FAULT
If you were to stand on
the fault and look along
its length, this is a type
of strike-slip fault where
the right block moves
toward you and the left
block moves away.

34. Performance Task (Create a FAULT MODEL)

35. 35