title: Asperity characteristics of the Olami-Feder-Christensen model of earthquakes.
abstract: Properties of the Olami-Feder-Christensen (OFC) model of earthquakes are studied by numerical simulations. The previous study indicated that the model exhibited "asperity"-like phenomena, i.e., the same region ruptures many times near periodically [T. Kotani, Phys. Rev. E 77, 010102(R) (2008)]. Such periodic or characteristic features apparently coexist with power-law-like critical features, e.g., the Gutenberg-Richter law observed in the size distribution. In order to clarify the origin and the nature of the asperity-like phenomena, we investigate here the properties of the OFC model with emphasis on its stress distribution. It is found that the asperity formation is accompanied by self-organization of the highly concentrated stress state. Such stress organization naturally provides the mechanism underlying our observation that a series of asperity events repeat with a common epicenter site and with a common period solely determined by the transmission parameter of the model. Asperity events tend to cluster both in time and in space.
authors.affiliation: Department of Earth and Space Science, Faculty of Science, Osaka University, Toyonaka 560-0043, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Kawamura
authors.forename: Takumi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kotani
authors.forename: Hajime
authors.initials: H
authors.lastname: Yoshino
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D055866:Earthquakes; D015233:Models, Statistical; D009991:Oscillometry / Q000379:methods*