Earthquake is one of the best - known examples of the response of the crust to a force within the earth.

1. WHAT IS AN EARTHQUAKE?
By Prof. Liwayway Memije - Cruz

2. Earthquake – is a
sudden release of
energy in the
Earth's crust.

3. SEISMOLOGY is the study of earthquakes . It studies
the frequency, type and size of earthquakes over a
period of time.
Earthquakes are measured using observations from
seismometers.

4. EARTHQUAKE FAULT TYPES
 Normal Fault
 Reverse Fault
 Strike-slip Fault

5. NORMAL FAULT (Dip-slip) - Occurs when
two plates pull away from each other.

6. REVERSE FAULT (Thrust) - Occurs
where two plates push together.

7. STRIKE-SLIP FAULT - Occurs where
two plates slip past each other

8. RICHTER
SCALE -
Used to rate
the amount
of energy an
earthquake
releases

9. HOW DO EARTHQUAKE WAVES TRAVEL?
• Seismic Waves
- Waves of energy that travel through the Earth away from
an earthquake.
• Surface Waves
- Seismic waves that travel along the Earth’s surface.
• Body Waves
- Seismic waves that travel along the Earth’s interior.
> P Waves
- Seismic waves that cause particles of rock to move in a
back and forth direction.
> S Waves
- Seismic waves that cause particles of rock to move in a
side to side direction.