1. Earthquakes
Pages C14-17

2. What is an Earthquake?
A vibration, or shaking of earth’s crust
During an earthquake, rock may move up and down, side to side, or both

3. What is a Fault? A break in the crust along which rock moves
Earthquakes occur along fault lines

4. Why is Focus Important?
This is the underground spot where the movement first happened
The epicenter is the surface point right above the focus.
This will be the place with the most violent movement and the most destruction.

5. How are Earthquakes Monitored?
A seismograph records earthquake waves.
A pen attached to the machine moves as the quake occurs, charting the strength of the movements.

6. Seismograph At Work

9. How are Earthquakes Measured?
Scale of numbers 1-9 used to measure the energy created by a quake is called the Richter Scale
Scale of Roman numerals I to XII used to measure earthquake energy is called the Mercalli scale.

10. Charles Richter

11. Review
What is an earthquake?
Shaking or vibration of Earth’s crust
What is a fault?
A break in the crust, along which rocks move

12. What happens at an earthquake’s focus?
The first movement occurs
Where is the epicenter located?
On the surface directly above the focus

13. The most violent movement/damage occurs at which point?
Epicenter