The document provides an overview of earthquakes, detailing their causes, types of faults, methods of measurement, and the behavior of seismic waves. It highlights the effects of earthquakes, including ground shaking, tsunamis, and landslides, and emphasizes the importance of earthquake preparedness through planning, emergency kits, and securing furniture. Overall, it serves as an educational guide for understanding and preparing for earthquakes.

1. COMMUNITY-
BASED DISASTER
RISK REDUCTION
AND
MANAGEMENT

2. Today, we embark on an exciting journey into the
fascinating world of earthquakes. We will explore
what causes earthquakes, the different types of
faults, how earthquakes are measured, the science
behind seismic waves and Earth's interior, the role
of seismographs, the effects of earthquakes, and
finally, earthquake preparedness
Welcome, students!

3. What is an Earthquake?
An earthquake is a sudden release of energy in the
Earth's crust that creates seismic waves.
What causes Earthquakes?
Most earthquakes occur due to the movement of
tectonic plates, which are large pieces of the Earth's
crust that fit together like a jigsaw puzzle.

4. Types of Faults
Faults are fractures or cracks in the Earth's crust where movement occurs.
Normal faults
Occur when rocks move
apart due to tensional
forces.
Reverse faults
Occur when rocks are
pushed together due to
compressional forces.
Strike-slip faults
Occur when rocks slide
horizontally past each other
due to shear forces.

5. Magnitude of
an Earthquake
• Magnitude is a measure of the
energy released by an
earthquake.
• The Richter scale is used to
measure the magnitude of an
earthquake, ranging from 0 to
10 or more.
• Each whole number increase on
the scale represents a tenfold
increase in the amplitude of the
seismic waves.

6. Seismic Waves
Seismic waves are the energy waves
that radiate outward from an
earthquake's epicenter.
• Primary (P) waves: Fastest waves
that compress and expand rocks in
the direction of wave propagation.
• Secondary (S) waves: Slower waves
that shake the ground
perpendicular to their direction of
travel.
There are two main types
of seismic waves
Surface waves: Slowest waves that
move along the Earth's surface and
cause the most damage.

7. Seismograph
• A seismograph is an instrument used to record and measure
the motion of the ground during an earthquake.
• It consists of a stationary base and a suspended weight or mass
that remains stationary during an earthquake but records the
motion of the ground.

8. EFFECTS
OF
AN
EARTHQUAKE
Ground shaking:
Can cause buildings, bridges, and other structures to
collapse.
Tsunamis:
Underwater earthquakes can generate large ocean
waves that travel long distances.
Landslides:
Slopes become unstable, leading to the downhill
movement of soil and rocks.

9. Earthquake
Preparedness
While we cannot predict when or where an
earthquake will occur, being prepared can
save lives and reduce damage.
• Create an emergency plan: Designate meeting
points, emergency contacts, and evacuation routes.
• Prepare an emergency kit: Include essentials like
food, water, first aid supplies, and a flashlight.
• Secure heavy furniture and objects: Use wall
brackets and fasteners to prevent them from falling
during an earthquake.
• Practice drop

10. ASSIGNMENT Week 1 Week 2 Week 3 Week 4
Presentation
Section 1: Notes
Section 1: Quiz
Section 2: Notes
Section 2: Quiz
Lab
Section 3: Notes
Section 3: Quiz
Stations
Flash Card Review
Chapter Test
CHAPTER 5: NATURAL HAZARDS