Geology, Earthquake

5. SCIENCE
CURIOSITY
NATURAL
SCIENCE
SOCIAL
SCIENCE
APPLIED
SCIENCE
PHYSICAL
SCIENCE
LIFE SCIENCE
PHYSICS
CHEMISTRY
ASTRONOMY
EARTH SCIENCE
Systematized
body of
knowledge
observing and
measuring

6. Unlike in previous grade levels, there
is only one strand in the Earth and
Space unit of Grade 10: GEOLOGY.
Module 1: PLATE
TECTONICS

9. OBJECTIVES
At the end of the lesson, the students are expected to:
a.Locate the epicenter of an earthquake using triangulation
method;
b.enumerate ways to ensure disaster preparedness during
earthquakes, tsunamis, and volcanic eruptions; and
c. suggest ways by which one can contribute to government
efforts in reducing damage due to earthquakes, tsunamis, and
volcanic eruptions.

10. ACTIVITY 1: FIND THE CENTER

11. This Photo by Unknown Author is licensed under CC BY-SA

12. LET’S CHECK
YOUR
KNOWLEDGE!

13. PRE -TEST

14. 1. It is the location on the Earth's
surface directly above the focus of an
earthquake.
a.center
b.direct center
c.epic center
d.epicenter

15. 2. What do we call the continuously
moving part of the earth’s crust?
a.fault
b.fissure
c.fracture
d.plate

16. 3. From the seismogram, the distance to
the epicenter can be determined by
measuring____.
a.the arrival time of surface wave
b.the difference in the arrival times of
the P and S-waves
c. the ratio of the amplitude of the
largest P and S-waves
d.the speed of the surface wave

17. 4. You were provided with data showing the
arrival time of the P and S-waves recorded
from three seismic stations. Which of these
can you possibly determine?
a.the damage at the focus
b.the intensity of the
earthquake
c. the distance to the
earthquake
d.the location of the epicenter

18. 5. Why is it important to be aware of
places prone to earthquakes?
a.to identify what crop must be
stored
b.to identify when to evacuate
c.to locate where to stay best
d.to perform necessary
precautions

20. 1. It is the location on the Earth's
surface directly above the focus of an
earthquake.
a.center
b.direct center
c.epic center
d.epicenter
Answer

21. 2. What do we call the continuously
moving part of the earth’s crust?
a.fault
b.fissure
c.fracture
d.plate
Answe
r

22. 3. From the seismogram, the distance to
the epicenter can be determined by
measuring____.
a.the arrival time of surface wave
b.the difference in the arrival time of
the P and S-waves
c. the ratio of the amplitude of the
largest P and S-waves
d.the speed of the surface wave
Answer

23. 4. You were provided with data showing the
arrival time of the P and S-waves recorded
from three seismic stations. Which of these
can you possibly determine?
a.the damage at the focus
b.the intensity of the
earthquake
c. the distance to the
earthquake
d.the location of the epicenter
Answer

24. 5. Why is it important to be aware of
places prone to earthquakes?
a.to identify what crop must be
stored
b.to identify when to evacuate
c.to locate where to stay best
d.to perform necessary
precautions
Answer

25. What is an Earthquake?

26. Let’s find the
meaning!
○Earthquake
○Epicenter
○Focus
○Seismology
○Seismologist
○Seismograph
○Seismogram
○Seismic Waves
○P-waves
○S-waves

27. EARTHQUAKES/TREMOR
• Definition
1. a shaking or vibration of the ground

28. • Why?
1. breakage of the ground along a fault
2. elastic rebound theory

29. Anatomy of an earthquake
1. focus
2. epicenter
3. slip
4. seismic waves

30. Seismologists
are scientists who study
earthquakes and planetary
activities as well as their effects,
such as tsunamis. They use
instruments to gather data and
monitor the Earth's crust.

31. Seismic Waves
1. measure with a seismograph

32. Detecting Earthquake
SeismograPH

33. Detecting Earthquake
SeismograM

34. Seismic Waves
(1) P-waves
(2) S-waves

37. Find the Epicenter
(Adapted and modified from the Learner’s
Material)
•Map for Learning
Task 1 (NOTE:
Dots represent
the Seismic
Stations)
.
.
.

39. Study the data showing the difference in the arrival
time of P-wave and S-wave on three seismic
recording stations.
Station Td km Scaled
distance
cm(radius
of the circle)
cm(diamete
r of the
circle)
Occidental Mindoro 62.4 s
Samar 32.8 s
Zamboanga del
Norte
36.8 s

40. Procedure
• 1. Compute the distance of the epicenter from each of the stations
using this formula:
𝑑 =
𝑡𝑑
8 𝑠
𝑋 100 𝑘𝑚
where: d = distance (km)
td = time difference in the arrival time of P-wave and S-wave
(seconds)
This formula is suited because 8 seconds is the interval between the
times of arrival of the P-wave and S-wave at a distance of 100 km.

41. Procedure
•2. Choose one of the recording stations and
measure the computed distance on the scale
(the scale of the map is 1 cm: 100 km).
Set your compass for that computed distance.
Center your compass on the station you have
chosen. Draw a circle.

42. Procedure
•3. Repeat steps 3 and 4 for the rest
of the stations. You should get
three circles that intersect or
nearly intersect at a point. This
intersection is the epicenter.

43. Do the Activity: Activity 1 Find the
Center

44. Study the data showing the difference in the arrival
time of P-wave and S-wave on three seismic
recording stations.
Station Td km Scaled
distance
cm(radius
of the circle)
cm(diamete
r of the
circle)
Occidental Mindoro 40 s
Samar 32 s
Zamboanga del
Norte
36 s

45. Assessment:
Review for a short quiz on the next
meeting about our lesson for today.