HR: 0800h
AN: S21B-0576    [Abstracts]
TI: 3D Dynamic Crack Rupture by a Finite Volume Method
AU: * Ben Jemaa, M
EM: Mondher.Ben_Jemaa@inria.fr
AF: INRIA-ENPC, Caiman Project, 2004 Route des Lucioles, BP 93, Sophia Antipolis, F-06902, France
AU: Glinsky-Olivier, N
EM: Nathalie.Glinsky@inria.fr
AF: INRIA-ENPC, Caiman Project, 2004 Route des Lucioles, BP 93, Sophia Antipolis, F-06902, France
AU: Cruz-Atienza, V M
EM: cruz@sciences.sdsu.edu
AF: Deparment of Geological Sciences, San Diego State University, SDSU 5500 Campanile Drive, San Diego, CA 92182-1020, United States
AU: Virieux, J
EM: Jean.Virieux@obs.ujf-grenoble.fr
AF: LGIT-Université Joseph Fourier Maison des Géosciences, BP 53, Grenoble cedex 9, 38041, France
AB: Dynamic rupture of a 3D spontaneous crack of arbitrary shape has been investigated using a Finite Volume (FV) approach. The full domain is decomposed in tetrahedra while the surface on which the rupture is supposed to take place is discretized with triangles which are faces of tetrahedra. Because of this meshing strategy, any shape of the rupture surface could be designed and is performed once before simulations start. First of all, the elastodynamic equations are described into a pseudo-conservative form for easy application of the FV discretisation. Explicit boundary conditions are given using criteria based on the conservation of discrete energy through the crack surface. Using a stress-threshold criterion, these conditions specify fluxes through those triangles which have suffered rupture. On these broken surfaces, stress follows A linear slip-weakening law although other friction laws can be implemented as well. Numerical solutions on a planar fault are achieved for the problem version 3 of the SCEC community dynamic-rupture benchmark exercise (Harris and Archuleta, 2004) and compared with those provided by a Finite Difference (FD) technique (Day et al, 2005). Another benchmark problem is also tackled involving a nonplanar curved fault (Cruz-Atienza et al, 2007). Solutions for this difficult exercise are compared with those computed with a Boundary Integral (BI) method (Aochi et al, 2000). In both benchmarck problems, comparisons show that rupture fronts are well modelled with a slight delay in time especially along the antiplane direction related to the low-order interpolation of the FV approach which requires further mesh refinement or/and an higher-order interpolation strategy as for Galerkin Discontinuous approach. Slip-rate and shear stress amplitudes are well modelled as well as stopping phases and stress overshoots. We expect this method, which is well adapted to multi-preocessor parallel computing to be competitive with others for solving large scale dynamic ruptures scenario of seismic sources in the near future. References : Aochi, H., E. Fukuyama and M. Matsuura, 2000. Spontaneous rupture propagation of a non-planar fault in 3D elastic medium, PAGEOPH, 157, 2003-2027. Cruz-Atienza, V.M., J. Virieux, J. and H. Aochi, 3D finite-difference dynamic-rupture modeling along nonplanar faults, Geophysics, 72, SM123-SM137. Day, S. M., L.A. Dalguer, N. Lapusta and Y. Liu, 2005, Comparison of finite difference and boundary integral solutions to three-dimensional spontaneous rupture: Journal of Geophysical Research, 110, B12307, http://dx.doi.org/10.1029/2005JB003813. Harris, R. A. and R. J. Archuleta, 2004, Earthquake rupture dynamics: Comparing the numerical simulation methods: EOS, 85, 321.
DE: 4255 Numerical modeling (0545, 0560)
DE: 7209 Earthquake dynamics (1242)
DE: 7260 Theory
DE: 7290 Computational seismology
DE: 8118 Dynamics and mechanics of faulting (8004)
SC: Seismology [S]
MN: 2007 Fall Meeting