Seismic gaps are sections of plate boundaries that have notruptured in the recent past. A seismic gap is a segment of anactive fault known to produce significant earthquakes that hasnot slipped in an unusually long time, compared with other segments along the same structure Seismic gaps are the places where faults are ‘locked’ and the fault has not moved for a while, strain has built up. The longer it is locked, the more strain is built up.