Hi Glen,

It is my understanding that a fair amount of peer-reviewed research has been done on seismic gaps. To the best of my knowledge the term is used by seismologists exclusively for subduction zones, where it means that there have been major subduction events on two or more "segments" of the downgoing slab, leaving a segment in-between (laterally - a segment along the strike of the fault). The theory states that, where this is the case, there is a considerably heightened probability that the intervening segment will experience its event during any given period of time. I think that the theory has not found much favor, but has not actually been disproven. Keep in mind that the foregoing is probably inaccurate, and could be improved upon by a professional. I suspect there is a corresponding theory for strike-slip events. In either case, it certainly seems intuitive that it would be true, but, IIRC, it just seems to be one more confounding failed expectation.

Michael Williams
Arroyo Grande, CA USA