2. Content Standard:
The learner demonstrates understanding of
the relationship among the locations of
volcanoes,
earthquake epicenter, and mountain ranges
20XX PRESENTATION TITLE 2
3. Performance Standard:
The Learners shall be able to
demonstrate ways to ensure disaster
preparedness during earthquakes,
tsunami, and volcanic eruption
20XX PRESENTATION TITLE 3
4. LEARNING
COMPETENCIES/OBJECTIVES
20XX PRESENTATION TITLE 4
1. Describe the distribution of active volcanoes,
earthquake epicenters,
and major mountain belts.
2. Describe the different types of plate
boundaries.
3. Explain the different processes that occur
along the plate boundaries.
8. MAJOR EARTHQUAKE IN THE PHILIPPINES
20XX PRESENTATION TITLE 8
Moro gulf Earthquake ( MAGNITUDE 8.1)
9. MAJOR EARTHQUAKE IN THE PHILIPPINES
20XX PRESENTATION TITLE 9
Moro gulf Earthquake ( MAGNITUDE 8.1)
1976
10. MAJOR EARTHQUAKE IN THE PHILIPPINES
20XX PRESENTATION TITLE 10
Luzon Earthquake ( MAGNITUDE 7.8)
1990
11. MAJOR EARTHQUAKE IN THE PHILIPPINES
20XX PRESENTATION TITLE 11
Lanao Earthquake ( MAGNITUDE 7.5)
1955
12. MAJOR EARTHQUAKE IN THE PHILIPPINES
20XX PRESENTATION TITLE 12
Casiguran Earthquake ( MAGNITUDE 7.3)
1368
13. 20XX PRESENTATION TITLE 13
3 types of seismic wave
PRIMARY WAVE
SECONDARY WAVE
LONG SURFACE WAVES
• Love waves
• Rayleigh wave
14. HOW DO WE LOCATE THE EPICENTER?
20XX PRESENTATION TITLE 14
If we have at least three recording stations
that can tell how far away
from them the earthquake occurred, the
epicenter can be determined using the
TRIANGULATION METHOD
18. 18
Activity 1
Find the Center
Objective:
Locate the epicenter of an earthquake using the
triangulation method.
Materials:
• hypothetical records of earthquake waves
• Philippine map
• drawing compass and rule
20. 20XX PRESENTATION TITLE 20
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.
Lithosphere consists of crust and the upper portion of the mantle. Figure 1 in the LM shows two types of crust, the continental crust and the oceanic crust. The continental crust is thicker but less dense than the oceanic crust. Because of the difference in density, continental crust floats higher than the oceanic crust.
Derived from the Greek word LITHOS meaning Rocky/Stone. This word is coined by JOSEPH BARRELL (1914) WHO FIRST STUDY THE MOTION OF LITHOSPHERE OVER MOLTEN LAYER.
Figure 2 in the LM is a map showing the lithosphere of the Earth divided into the segments called plates. But what are the Basis of scientists imn dividing the lithosphere is such manner?
The plates move very slowly but constantly, and this movement is called tectonics; thus the theory of moving lithospheric plates is called plate tectonics.
in your Grade 8 Science that an earthquake releases three types of seismic waves; Primary (P-waves), Secondary (S-waves), and Long surface waves (L-waves).
The first two travel into the Earth’s interior while the last one on the surface
. These waves travel at different velocities; thus, do not arrive at a seismic recording station at the same time. The farther
the recording instrument is from the focus, the greater the difference in arrival times of the first P-wave compared to the first S-wave. The difference in the arrival time will tell us the distance of the earthquake’s focus from the seismic recording station. However, it does not tell in which direction it came from.
. It uses distance information from three seismic stations to locate the earthquake epicenter. On a map, circles are drawn around each seismic station.
. The radii of the circles are scaled to the estimated distance from the station to the earthquake. The three circles will intersect at one point that locates the earthquake.
The three circles will intersect at one point that locates the earthquake. The point of intersection is the location of the epicenter.
Cebu is the epicenter
Assuming that the two circle will intersect the circle will intersect at two point , it means there are two epicenter
But, if the earthquake
took place at a far greater distance, seismologists use the distance-time graph
similar to the figure below in determining the location of the epicenter.
S-P interval is 10 minutes
What is the distance of the epicenter from the seismic station?
Answer: 9000 km
Determining the location of earthquake epicenters plays a vital role
in laying the foundations of plate tectonics
Locating earthquake epicenters will pinpoint which fault lines are active.
Usually, the less active fault line stores great amount of potential energy
that could cause major earthquake once released. Therefore, places near
fault lines that remain inactive for a long period of time are due to experience
a major earthquake.