The failure of an asperity, ie the dynamic rupture of a small fault area with finite stress drop surrounded by a broken or weak fault area which has no stress drop but which slips after the asperity fails, is proposed as a model for the rupture process of a subevent in a composite earthquake. The rupture area of the composite earthquake surrounding the subevent is modeled by the weak fault area surrounding the asperity in the subevent model. The resulting seismic moment of the subevent is proportional to the stress drop and the rupture area of the subevent, as well as the radius of the composite earthquake. By setting the stress drops of the asperity models equal to the dynamic stress drops of the subevents, the composite earthquake can be modeled as the sum of a set of subevents which cover the rupture area of the composite earthquake.-from Author
Additional publication details
The seismic radiation from composite models of faulting.