Michael,

Let's see what I can do to clarify:
How does one judge potential magnitude? Just by length of tone, meaning the longer it is the further away it is the larger the eq?

The Length of the tone tells you how far away the earthquake should be, but the volume normally tells you how large an earthquake. BUT, BUT some areas produce sounds which are loud for smaller end quakes and those are along the areas of Oceanside/San Diego and all of Baja, Markleville, Lee Vining, Mammoth and Bishop and a few scattered areas in northern CA, like Somes Bar.

When your basing a prediction on an ear tone, why not just make a prediction for a geographical ring rather than a single point? Or, better yet, the points that your ring cross active faults?

Actually there is a round area most of the time, it's the radius which is normally 37.5 miles. IE: the equivalent of one second of ear tone to allow for counting errors. BUT, if the tone is long one has to allow for more margin of error, so the radius has to be adjusted for this margin.

Nothing which fault may be involved depends entirely on the area. Central CA with Parkfield on one side and San Simeon on the really defines the area well, but in the central Bay Area and Metro LA are to complicated.

In the end two things are really beneficial: 1. Memory and 2. Knowledge of geology and seismicity. But at times there's nothing to draw upon and so you have to wing it as best you can....LOL A little luck never hurts.

Petra