Seismogenic fault

A fault that is capable of generating earthquakes. 

The brittle tectonic element either causative of a particular seismic event/mainshock(s) of a given sequence or deemed potentially responsible for a future one.

It is recognized and defined using all available geological and geophysical data suitable for its identification thus depending on constraints including (but not limited to) its dimensions its structural position and its effects on the ground-surface (if any whether ductile or brittle).