"The size and magnitude of an earthquake is measured in several different ways. The Richter Scale measures the size of earthquake waves. It was developed by Charles Richter in the 1930s and is a logarithmic measurement of the amount of energy released by an earthquake, See: Below. The Mercalli Intensity Scale evaluates the intensity of a quake according to observed severity at specific locations. It rates the intensity on a Roman numeral scale that ranges from I to XII. Today, seismologists are using the Moment Magnitude Scale, which measures the size of the earthquake's fault, and how much of the earth slips at the time of the quake. A number of readings are taken, averaged and then adjusted to generate numbers similar to the Richter Scale. This allows the magnitude of earthquakes measured on these new scales to be compared with earthquakes recorded earlier. According to the Moment Magnitude Scale, the severity of an earthquake is categorized as the following: 5.0 Small 5.0 - 6.0 Moderate 6.0 - 7.0 Large 7.0 - 7.8 Major 7.8 Great" (Insurance Information Institute, Earthquakes...., May 2008)