Hi All,

You probably know by now, math is not my best subject. I had dyslexia in my youth and never caught on. So when I don't know, I ask. At least the questions get answered.

I'm trying to measure b-value for a local fault. In the past ten years its only had four quakes. Two before a moderate event and one after. Therefore if one uses the ten year catalog, as follows and averages them, it's a 2.9, to high for b-value to apply to a major quake in the area.

3.5, 1.5, 5.17, 1.4 = 11.6 divided by 4 = 2.9, correct?

Now heres the tricky part. b-value is calculated on averaging from the catalogs and then this is applied:

"When b is determined for a seismically active region, the total seismic energy released over a period can be calculated by using the energy factor. Magnitude is also sometimes roughly estimated from the length of surface fault rupture L (in kilometers). These calculations all follow from substitutions of measurements made directly on the seismogram into empirical formulas." B. Bolt 1993 "Earthquakes"

The average of b value in 1993 was .08 for the Bay Area. So do I need to obtain catalogs for more than 10 years, since only four showed up in ten years? Then how does one figure out part 2? Gosh, what a mental twist.

So those willing to try and explain it to me, please use simple terms. I need all the help I can get. Its terrible to want to figure these things out and know you haven't got the mentals to do so. I guess that's why God didn't make us all the same. I'm better at artistic pursuits. Anyone want to know the meaning of colors?

Nah, this is serious stuff.....Petra