73 Stress triggers, stress shadows, and seismic hazard

Abstract

This chapter focuses on stress trigger, stress shadows, and seismic hazard. In addition to static stress changes, dynamic or transient stress changes may be capable of triggering earthquakes. There is evidence from a few large and great earthquakes that distant triggering has occurred. Many models of static or dynamic stress changes influencing subsequent earthquake occurrence apply to a particular tectonic setting and for one earthquake cycle or less. Some research has been conducted to evaluate longer-term effects, including multiple earthquake cycles. Using synthetic seismicity models, and running for hundreds or hundreds of thousands of earthquake cycles, fault interaction has been shown to have a large impact on the timing and location of simulated earthquakes. There are also hypotheses that present ideas about earthquake patterns vastly different from simple elastic or viscoelastic fault interaction models. If one studies great earthquakes, one can use simple models such as Coulomb failure to explain where and when no (or few) large aftershocks occurred. After a great or large earthquake, one can also study the large aftershocks that did occur, and use simple models, such as Coulomb failure, or complex models, such as rate-and-state friction, to explain their occurrence.