HR: 1340h
AN: S13B-1307    [Abstracts]
TI: Investigating the Effects of Stress Interaction Using a Cellular-automaton Based Model in Fault Networks of Varying Complexity.
AU: * Hetherington, A P
EM: hetherington-a1@ulster.ac.uk
AF: School of Environmental Sciences University of Ulster, Coleraine Campus Cromore Road County Londonderry, Coleraine, BT52 1SA, United Kingdom
AU: Steacy, S
EM: s.steacy@ulster.ac.uk
AF: School of Environmental Sciences University of Ulster, Coleraine Campus Cromore Road County Londonderry, Coleraine, BT52 1SA, United Kingdom
AU: McCloskey, J
EM: j.mccloskey@ulster.ac.uk
AF: School of Environmental Sciences University of Ulster, Coleraine Campus Cromore Road County Londonderry, Coleraine, BT52 1SA, United Kingdom
AB: Seismicity spatial and temporal patterns are strongly influenced by stress interaction between faults. However the effects of such interaction on earthquake statistics is not yet well understood. Computer models provide accurate, large and complete datasets to investigate this issue and also have the benefit of allowing direct comparison of seismicity behavior in time and space in networks, with and without fault interaction. We investigate the effect of such interaction on modeled real-world fault networks of varying complexity using a cellular-automata based model. Each 3-D fault within the fault network is modeled by a discrete cellular automaton. The cell size is 1 km square which allows for a minimum earthquake size of approximately Mw=4. The cell strength is distributed fractally across each fault and all cells are loaded by a remote tectonic stressing rate. When the stress on a cell exceeds its strength, the cell fails and stress is transferred to its nearest neighbors which may in turn cause them to break allowing the earthquake to grow. These stress transfer rules allow realistic stress concentrations to develop at the boundary of the rupture. If the extent of the rupture exceeds a user defined minimum length, and if interaction between faults is allowed, a boundary element method is used to calculate stress transfer to neighboring faults. Here we present results from four simulated fault networks based on active faults in the San Francisco Bay Area, California, the Northern Anatolian Fault, Turkey, Southern California, and the Marlborough Fault System, South Island, New Zealand. These are chosen for their varying level of fault complexity and we examine both interacting and non-interacting models in terms of their b-value and recurrence intervals for each region. Results will be compared and discussed.
DE: 4499 General or miscellaneous
DE: 7209 Earthquake dynamics (1242)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting