HR: 10:20h
AN: S22A-01    [Abstracts]
TI: Fault complexity, interaction, and the Gutenberg-Richter relation
AU: * Steacy, S
EM: s.steacy@ulster.ac.uk
AF: University of Ulster, Cromore Road, Coleraine, BT52 1SA Ireland
AB: Although the Gutenberg-Richter relation is one of the most fundamental observations in earthquake physics, there is still controversy as to whether power-law regional magnitude frequency statistics apply to individual faults. A number of observations suggest that earthquake populations on particular faults are better described by a weakly characteristic model in which a greater number of large events is observed than is expected from the power-law distribution of smaller ones. Such observations are problematical, however, due to the weak statistics of the small number of large events and the effect of box size on the perceived distribution. Here we investigate this problem in a complex fault network model which combines nearest-neighbor stress transfer on individual faults with Coulomb stress transfer between faults. We find that the regional m-f distribution depends on both fault structure and the degree of interaction with more power-law behavior observed with both increased fault complexity and interaction. We further observe that m-f distributions on individual faults can be quite different from the regional m-f distribution. These results have important seismic hazard implications as they suggest that extrapolation of the expected number of large events from the observed population of smaller ones may not be generally appropriate for individual faults, even if the regional m-f distribution is power-law.
DE: 7223 Seismic hazard assessment and prediction
DE: 7260 Theory and modeling
DE: 7209 Earthquake dynamics and mechanics
SC: Seismology [S]
MN: 2004 AGU Fall Meeting