HR: 1340h
AN: S13D-1097    [Abstracts]
TI: Rheological Models in the Time-Domain Modeling of Seismic Motion
AU: * Moczo, P
EM: moczo@fmph.uniba.sk
AF: Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, Bratislava, 842 48 Slovakia (Slovak Republic)
AU: Kristek, J
EM: kristek@fmph.uniba.sk
AF: Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, Bratislava, 842 48 Slovakia (Slovak Republic)
AB: The time-domain stress-strain relation in a viscoelastic medium has a form of the convolutory integral which is numerically intractable. This was the reason for the oversimplified models of attenuation in the time-domain seismic wave propagation and earthquake motion modeling. In their pioneering work, Day and Minster (1984) showed the way how to convert the integral into numerically tractable differential form in the case of a general viscoelastic modulus. In response to the work by Day and Minster, Emmerich and Korn (1987) suggested using the rheology of their generalized Maxwell body (GMB) while Carcione et al. (1988) suggested using the generalized Zener body (GZB). The viscoelastic moduli of both rheological models have a form of the rational function and thus the differential form of the stress-strain relation is rather easy to obtain. After the papers by Emmerich and Korn and Carcione et al. numerical modelers decided either for the GMB or GZB rheology and developed 'non-communicating' algorithms. In the many following papers the authors using the GMB never commented the GZB rheology and the corresponding algorithms, and the authors using the GZB never related their methods to the GMB rheology and algorithms. We analyze and compare both rheologies and the corresponding incorporations of the realistic attenuation into the time-domain computations. We then focus on the most recent staggered-grid finite-difference modeling, mainly on accounting for the material heterogeneity in the viscoelastic media, and the computational efficiency of the finite-difference algorithms.
DE: 7260 Theory and modeling
SC: Seismology [S]
MN: 2004 AGU Fall Meeting