Fault death: a perspective from actively deforming regions

Patterns of activity on large faults in regions of distributed continental deformation can change quite rapidly (in less than 1 Ma). Such changes include faults becoming permanently or temporarily inactive, spatial migration of activity between different faults or faults sets within a deforming region, and faults apparently going through episodes of intense activity separated by long quiescent periods. Greater knowledge of these changes, combined with our increasingly detailed understanding of the geometry of large faults, have implications for a variety of structural and tectonic issues, such as: (1) the nature of the interaction between neighbouring faults; (2) the link between the discontinuous deformation on faults in the seismogenic upper crust and the more distributed deformation in the aseismic lithosphere beneath; and (3) the relation between the instantaneous kinematics and the cumulative, finite deformation. Examples from the active extensional province of central Greece are used to illustrate the nature and possible significance of changing fault patterns.