The Richter Magnitude is a number that is used to measure the size of an earthquake. The magnitude is a measure of the strength of the seismic waves that have been sent out from the focus. A scientist uses a seismograph to determine the strength of the earthquake. A seismograph is an instrument that measures the amount of ground motion that an earthquake produces.

Each number on the Richter Scale represents an earthquake that is ten times as powerful as the number below it.

Examples: An earthquake measuring 6 is ten times stronger than a magnitude 5 quake. An earthquake of a magnitude 9 is 10,000 times more powerful than a 5.

The strongest earthquake ever measured was a 8.9 off of the coast of Ecuador in 1906. Earthquakes of 6 and above are considered major quakes. Earthquakes of 7 and above have the ability to do great damage and kill many people.

Click on the "Next" button to see what a seismic reading looks like!