The Richter scale has no lower limit and no maximum, the Associated Press reports. It's a "logarithmic" scale, which means that each one-point increase on the scale represents a 10-fold increase in the magnitude of the quake.
As Scholastic.com explains: "An earthquake registering 2.0 on the Richter scale is 10 times stronger than a quake registering 1.0. A quake registering 3.0 is 10 X 10 or 100 times stronger than a quake registering 1.0 A 4.0 is 10 X 10 X 10 or 1,000 times greater than 1.0 and so on."
» 10 things to know about earthquake that rattled Georgia
» How common are earthquakes in Georgia?
Minor: 2.5 or lower on the Richter scale. It is seldom felt, but can be recorded by a seismograph.
Light: 2.5 to 5.4. These are often felt, but usually cause only minor damage
Moderate: 5.5 to 6.0. Buildings might be slightly damaged
Strong: 6.1 to 6.9. Can cause a lot of damage
Major: 7.0 to 7.9. A major earthquake will likely cause serious damage
Great: 8.0 or higher. An earthquake of this magnitude can destroy communities near its epicenter.