Hi Chris,

Imagine a bulls eye. Fairbanks is at the center and the 5.0 would be assigned at the center. For every 25 miles outward you add .5, thus at 25 miles from Fairbanks you would expect a quake of 5.5. At 50 miles it would be a 6.0 and so on and so forth.

The concept is to have an earthquake at Fairbanks which "feels like" a 5.0, even if its higher, further away.

Because of your arrival time here, unfortunately, you missed our illustrious Dennis Gentry who used to predict quakes in CA using concentric circles all of the time. For awhile there, he had a hit ratio anyone would have enjoyed. He had a couple of pieces of home brew equipment and at times it performed very well.

Hope this helps....Petra