Map Key: Red, Zone 4; Orange, Zone 3; Yellow, Zone 2B; Green, Zone 2A; Blue, Zone 1.

A seismic zone map is based on a statistical compilation of the number and the magnitude of past earthquakes. Therefore, it is an indication of where the next earthquake is most likely to occur, how often and the magnitude. There is no direct correlation between seismic zone and Richter scale, except past experience shows that the worst earthquakes occur in the higher seismic zones.