Yo, Chris,

I'm working entirely from (faulty) memory here, but I don't think the North Anatolian quakes constitute a "gap" in the sense it is normally used by seismologists. For one thing, the N.A. is a strike-slip fault, and, for some reason, the term has been co-opted by subduction zones. But, also, IIRC, the Anatolian has been experiencing a rather unusual progression of events marching steadily from east to west. The publications you refer to have, quite reasonably it would seem, simply pointed out that the very next segment to the west is the one next to (under?) Istanbul. Though, the considerably earlier event to the west of that segment does sort of produce the "gap" you refer to.

Michael Williams
Arroyo Grande, CA USA