Are Simple Models Adequate for the Simulation of Recurrent Seismicity?

Monday, October 8, 2001 - 9:30am - 10:30am
Keller 3-180
Leon Knopoff (University of California, Los Angeles)
Recent statistical studies indicate that the magnitude-frequency relation for earthquake mainshocks is not scale-independent. A number of geophysical observations indicate consistency of the statistics with a fracture model for larger earthquakes that involves physics on at least four interactive scales. Because of computational limitations, it is doubtful that we will be able to take into account all of the different issues of the physics of fracture of this rather complicated model in constructing an appropriate computational model. We discuss the influence of the dynamics of fracture, the radiation of elastic waves, tensor stresses, the physics of nucleation and healing, the geometry of faults, three dimensionality and fault structure, and the influence of fluids and microfracturing and granularity on the properties of materials, in modeling the full problem. We discuss the robustness of simulations to the inclusion of some of these ingredients into models for the space-time pattern formation of mainshocks.