Seismic gap / quiet

Seismic gap theory predicts that large earthquakes in a particular place will always occur at specific intervals. Seismic quiet theory forecasts that usual seismic activity in an area will decrease just before major quakes. Both concepts are based on comparatively simple processes in the geological underground, e.g. where different faults do not influence each other, and each quake completely dissolves the prevailing tension caused by a fault system. Neither assumption applies in the most active fault zones and there are no metrics to support either theory.