An indicator for large earthquakes -Seismic quiescence

                                                   Yi-Xuan Wu

                  Institute of Geophysics, NationalCentralUniversity, Chungli, Taiwan 320.

                                            ABSTRACT

               Hainzl et al. [1999] proposed a 2-D modified string-block model, they introduce a 
             crust relaxation process in a continuous cellular automaton version of the Burridge and 
             Knopoff [1967] model. The most important model parameters are the level of 
             conservation and the ratio of the crust relaxation time to the tectonic reloading time. The 
             model reproduces many phenomena that also can be observed in real fault system; that is, 
             the various results of the simulation of the model agree with the phenomena observed 
             from real earthquake system. The principal new result obtained with this model is the 
             spatiotemporal clustering of events exhibiting several characteristics of earthquakes in 
             nature. Large events are followed by aftershock sequences obeying the Omori [1894] law 
             and preceded by localized foreshocks, which are initiated after a time period of seismic 
             quiescence. From the model, a successful simulation about that the stronger and the 
             longer the duration of this period, the larger on average is the subsequent mainshock may 
             confirm that seismic quiescence can be an indicator for large earthquakes.

                                            REFERENCE 

              Hainzl, S., G. Zoller, and J. Kurths, Seismic quiescence as an indicator for large 
              earthquakes in a system of self-organized criticality, Geophys. Res. Lett., 27, 597–600, 2000.

                                             (Abstract)(Full text)
              
              Hainzl, S., G. Zoller, and J. Kurths, Similar power laws for foreshock and aftershock 
              sequences in a spring-block model for earthquakes, J. Geophys. Res., 104, 7243-7254, 1999. 
                                        
                                             (Abstract)(Full text)