Earthquakes

Today I am going to tell you about earthquakes. Earthquakes are vibrations in the ground that result from movement along breaks in earths lithosphere. These breaks are called faults. Earthquakes began at faults.Faults are breaks in earths lithosphere. Earthquakes are measured by a richter scale. Seismologists use richter scales. Richter scales go's up to 10. 

 P-waves are the fastest waves out of all the waves. P-waves are the first waves you feel. S-waves are slower than p-waves. They cause particles in the ground to move up and down at right angles relative to the direction the wave travels. There is one more wave and that wave is the seismic wave. These waves originate where rocks first move along the fault at a location inside earth called the focus. 

 http://earthquake.usgs.gov/learn/kids/
http://earthquake.usgs.gov/learn/facts.php

http://www.weatherwizkids.com/weather-earthquake.htm