HR: 17:45h
AN: S14B-08    [Abstracts]
TI: Correlations and Non-predictability in the Time Evolution of Earthquake Ruptures
AU: * Elkhoury, J E
EM: elkhoury@ess.ucla.edu
AF: Institute of Geophysics & Planetary Physics, University of California, Los Angeles, CA 90095, United States
AU: * Elkhoury, J E
EM: elkhoury@ess.ucla.edu
AF: Department of Earth & Space Sciences, University of California, Los Angeles, CA 90095, United States
AU: Knopoff, L
EM: lknopoff@jumpy.igpp.ucla.edu
AF: Institute of Geophysics & Planetary Physics, University of California, Los Angeles, CA 90095, United States
AU: Knopoff, L
EM: lknopoff@jumpy.igpp.ucla.edu
AF: Department of Physics & Astronomy, University of California, Los Angeles, CA 90095, United States
AB: The characterization of the time evolution of ruptures is one of the important aspects of the earthquake process. What makes a rupture, that starts small, to become a big one or end very quickly resulting in a small earthquake is central to understanding the physics of the time evolution of ruptures. Establishing whether there are any correlations in time, between the initiation of the rupture and its ultimate size, is a step in the right direction. Here, we analyze three source-time function data sets. The first is produced by the generation of repeated rupture events on a 2D heterogeneous, in-plane, dynamical model, while the second is produced by an-age dependent critical branching model. The third is the source-time function data base of Ruff [1]. We formulate the problem in terms of two questions. 1) Are there any correlations between the moment release at the beginning of the rupture and the total moment release during the entire rupture? 2) Can we predict the final size of an earthquake, once it has started and without any a posteriori information, by just knowing the moment release up to a certain time τ? Using the three data bases, the answer to the first question is yes and no to the second. The longer τ is, the stronger the correlations are between what goes on at the initiation and the final size. But, for τ fixed, and not a major fraction of the rupture time, there is no predictability of the rupture size. In particular, if a rupture starts with a very large moment release during time τ, it becomes a large earthquake. On the other hand, large earthquakes might start with very small moment release during τ; the non-predictability is due to the heterogeneities. The randomness in the critical branching model mimics the effect of the heterogeneities in the crust and in the 2D model. \begin{thebibliography}{99} \bibitem{ruff} Ruff, L. J., http://www.geo.lsa.umich.edu/SeismoObs/STF.html \end{thebibliography}
DE: 7209 Earthquake dynamics (1242)
DE: 7215 Earthquake source observations (1240)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7260 Theory
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting