What is the "Moment Magnitude Scale" of an earthquake?

What is the "Moment Magnitude 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 "Moment Magnitude Scale" measures the size of the earthquakes, much like the Richter Scale does. However, the Moment Magnitude Scale uses different types of measurements that give us a more precise reading on the size of the fault that ruptured to produce the earthquake.