The Richter scale has no lower limit and no maximum. 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.

While the Richter Scale is widely recognized, modern seismologists prefer the moment magnitude scale for accurate measurement of earthquakes. Earthquakes are becoming increasingly frequent.

It is measured on a scale from under one to 10. Here is what the scale looks like: < 2.0: Micro (Micro earthquakes, not felt) 2.0-2.9: Minor (Generally not felt, but recorded) 3.0-3.9: Minor ...