1. Earthquake Terms

2. Seismology
The study of Earthquakes

3. Faults
A break in the Earth’s crust along which blocks of the crust slide relative to one another
Earthquakes occur along faults because of this sliding.

4. Deformation – bending and breaking of Earth’s crust
Plastic deformation
Elastic deformation
Like a piece of molded clay
Does not lead to earthquakes
Like a rubberband
Sudden return of elastically deformed rock to its undeformed shape
Energy is released
Seismic waves cause Earthquakes

5. A wave of energy that travels through the Earth.
Seismic Waves
A wave of energy that travels through the Earth.

6. P waves
S Waves
A seismic wave that causes particles of rock to move in a back-and forth motion
Primary waves – pressure waves
Fastest waves
Can travel through solids, liquids, and gases
A seismic wave that causes particles of rock to move in a side-to- side motion
Secondary waves – shear waves
Second fastest waves
Cannot travel through liquid

7. Surface Waves
They move along the Earth’s surface and produce motion mostly in the upper few kilometers of Earth’s crust.
They move the ground much like ocean waves move water.
Travel more slow
More destructive