HR: 14:10h
AN: S32D-03    [PDF]
TI: Testing of hypotheses associated earthquake clustering features by using the stochastic reconstruction method
AU: * Zhuang, J
EM: zhuangjc@ism.ac.jp
AF: Institute of Statistical Mathematics, Minana Azabu 4-6-7, Minato-Ku, Tokyo, 106-8659 Japan
AU: Ogata, Y
EM: ogata@ism.ac.jp
AF: Institute of Statistical Mathematics, Minana Azabu 4-6-7, Minato-Ku, Tokyo, 106-8659 Japan
AU: Vere-Jones, D
EM: dvj@mcs.vuw.ac.nz
AF: Victoria University of Wellington, P.O.Box 600, Wellington, 00000 New Zealand
AB: Based on Ogata's ETAS model and the thinning procedure, we firt give an iterative approach to estimate the background occurrence rate, which is a function of locations but constant of time, and the parameters of the clustering struction, simultaneously. We then discuss the methods for sperating the seismicity in a given catalogue into a background component and a clustering component and for classifying the earthquakes into different clusters stochastically. The keys of these methods are the probabilities of one event being a direct offspring of another event or being a background event. Making use of these probabilities, we can reconstruct the functions associated with the characteristics of earthquake clusters, which enable us to test a number of important hypotheses about the earthquake clustering phenomena. In this paper, using the JMA catalogue for illustruction, the results show the following assertions: (a) The function forms provided on each clustering component in the formulation of Ogata's ETAS model are good enough as a first approximation in describing earthquake clusters; (b) the background events trigger offspring in a different ways from the triggered events; (c) The diffusion of the aftershock sequence is mainly caused by the cascades of individual trigger processes, while each individual process for triggering direct offspring is not diffusive; (d) the scales of the area of triggered events are mainly associated with the triggering ability of their direct ancestor.
DE: 3210 Modeling
DE: 7200 SEISMOLOGY
DE: 7209 Earthquake dynamics and mechanics
DE: 7223 Seismic hazard assessment and prediction
DE: 7230 Seismicity and seismotectonics
SC: Seismology [S]
MN: 2003 Fall Meeting