+IOW, the dogma that the length of a known fault determines the max size of a quake on the fault is not correct at all...that a mag. 7+ could occur anywhere on any fault(s) given particular conditions.

Say What? I guess the first thing to decide is which magnitude are you referring to? Magnitude is a measure of the strength of an earthquake or strain energy released by it.

What evidence could you possibly have to refute the given magnitude possibility on a fault? Have you mapped faults that are longer than what is officially mapped?

Richter magnitude is a logarithmic measurement of the amplitude of the wave produced on a standard Wood-Anderson type seismograph.

Seismic Moment = rigidity x rupture area x fault slip and rupture area = fault length x fault width
The moment magnitude is proportional to the area of the fault surface that has slipped. Thus, it is directly related to the fault length.

You can find an article here that shows the relation between fault length and magnitude:
http://geopubs.wr.usgs.gov/open-file/of84-256/ - specifially see page 11 of the full document.

Canie

• Magnitude and Intensity