%A Yehuda Ben-Zion
%A Mariana Eneva
%A Yunfeng Liu
%J Journal of Geophysical Research
%T Large earthquake cycles and intermittent criticality on heterogeneous faults due to evolving stress and seismicity
%X We analyze evolving stress and seismicity generated by three realizations of a discrete
model of a strike-slip fault in a three-dimensional (3-D) elastic half space using five
functions of stress and five functions of seismicity. The first model (F) has realistic
dynamic weakening (static minus dynamic frictions), the second (FC) has zero critical
dynamic weakening, and the third (SYS) is constrained to produce only system size
events. The results for model F show cyclical development, saturation, and destruction of
fluctuations and long-range correlations on the fault, punctuated by the system size events.
The development stage involves evolution of stress and seismicity to distributions having
broad ranges of scales, evolution of response functions toward scale-invariant behavior,
increasing seismicity rate and event sizes, and increasing hypocenter diffusion. Most
functions reach asymptotically stable values around 2/3 of the cycle and then fluctuate
until one event cascades to become the next large earthquake. In model FC the above
evolution is replaced by scale-invariant statistical fluctuations, while in model SYS the
signals show simple cyclic behavior. The results suggest that large earthquake cycles on
heterogeneous faults with realistic positive dynamic weakening are associated with
intermittent criticality, produced by spontaneous evolution of stress heterogeneities toward
a critical level of disorder having a broad range of scales. The stress evolution and
development of large earthquake cycles may be tracked with seismicity
functions.
%N B6
%V 108
%D 2003
%R doi:10.1029/2002JB002121
%I American Geophysical Union
%L epos1462