1. Earthquakes and Volcanoes
Two of nature’s examples of the Earth’s continuously moving crust.

2. Earthquakes

3. Earthquake Definition: Example
The shaking and trembling that results from the sudden movement of part of the Earth’s crust.
Example
Like throwing a pebble into a pond
Waves move outward in all directions
When rocks in the Earth’s’ crust break, earthquake waves travel through the Earth in all directions.

4. Major Causes What are the major causes of earthquakes? Faulting
Fault is a break in the earth’s crust along which movement occurs
Parts of earth’s crust are pushed together or pulled apart
Rocks break and slide past one another
Energy is released causing nearby rocks to move F A U L T I N G

5. Seismic Waves Focus Epicenter Point where rocks break and move
Underground point of origin
Epicenter
Directly above focus
Waves reach epicenter first
Most violent shaking
On earth’s surface