1. Earthquake Notes

2. What causes Earthquakes
Rocks are strained over time
Eventually the rocks break and snap back
Causes vibrations through the rock which become Earthquakes

3. Earthquake Waves Once the shaking starts it moves in seismic waves
Travels through rocks inside Earth as well as along the surface of the planet

4. Earthquake Focus and Epicenter
The place where the rock first breaks is called the focus
The point on the Earth’s surface directly above the focus is called the epicenter

5. Seismic waves Move in all directions from the epicenter
Waves traveling along the surface cause the most damage

6. Tsunamis When an earthquake occurs on the sea floor
Shock causes huge waves to form
Cause major damage and lose of life in sea side communities

7. Predicting Earthquakes
Changes in the rock before an earthquake are recorded and used to predict future earthquakes
Each earthquake is unique
Impossible to predict

8. P waves Primary waves Travel the fastest through rock material
Cause particles in the rock to vibrate in the same direction the waves are moving

9. S waves Secondary waves
Cause rocks to vibrate at a 90 degree angle to the direction the waves are moving

10. Richter Scale Describes how much energy an earthquake releases
Based on the height of the seismic waves as measured on a seismograph

11. Mercalli Intensity Measures the amount of damage done by an Earthquake
Depends on
The strength of the earthquake
The nature of the surface material
The design of structures
The distance from the epicenter