Earthquakes

Earthquakes are the moving of the Earth's plates, faults and features. Seismic waves are given off when an earthquake occurs. Their strength is measured using the Richter Scale.The seismograph is the instrument that records vibrations during an earthquake.

There are three type of earthquake waves:

P Waves or Primary Waves	S Waves or Secondary Waves	L Waves or Surface Waves
Characteristics -- First wave to be emitted, fastest, and causes the least amount of damage. This wave travels straight through the crust.	Characteristics -- Second wave to occur. It is slow moving and causes a limited amount of damage. This wave travels from side to side.	Characteristics -- This wave is also sometimes called a Love Wave. It is the last wave to occur and is the strongest. This wave has a rolling up and down motion much like an ocean wave. It travels along the surface of the earth and causes the most damage.
See a P Wave in Motion	See an S Wave in Motion	See an L Wave in Motion

See how P & S waves travel through the Earth