What is the "Richter Scale" of an earthquake?

What is the "Richter Scale" of an earthquake?

Tom Jordan (Director, Southern California Earthquake Center (SCEC)) gives expert video advice on: What is a geologic fault?; What is the "Richter Scale" of an earthquake?; What is the "Moment Magnitude Scale" of an earthquake? and more...

The Richter Scale was invented by Charles Richter in 1935, in Southern California, and was designed to measure the size of earthquakes, the size of fault ruptures that cause earthquakes specifically. Charles Richter did that by looking at the size of the waves that the earthquakes produced. The scale is based on measurements of the size of those waves.