In particular, earthquakes on mature and immature faults produce different amplitudes of slips and ground motions, whereas earthquake slips and speeds are systematically largest on the most mature sections of the ruptured zones. All these fault properties and their changes in relation to fault maturity markedly modify the earthquake behavior. As faults grow over the long-term and become more “mature”, some of their properties evolve: the damage zone enlarges and its compliance increases, the fault segments become more tightly connected, the fault plane roughness decreases as might also do the fault friction.
Faults also are systematically segmented laterally in a generic manner, and this segmentation divides their planes and produces strength and stress heterogeneities in a deterministic manner. Our group has been among the pioneers to show that faults are 3D features, systematically embedded in a permanent damage zone where crustal rocks are intensely faulted and hence are compliant. Here we argue that an important source of discrepancy is related to the incomplete integration of actual geometrical and mechanical properties of earthquake causative faults in existing rupture models. Yet, despite these efforts, major discrepancies still remain between available model outputs and natural earthquake behaviors. This topic has motivated many studies in last decades. Therefore, the best we can do is to mitigate their impact by anticipating the most “destructive properties” of the largest earthquakes to come: longest extent of rupture zones, largest magnitudes, amplitudes of displacements, accelerations of the ground. Decades of research on earthquakes have yielded meager prospects for earthquake predictability: we cannot predict the time, location and magnitude of a forthcoming earthquake with sufficient accuracy for immediate societal value.