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| Abstract | We employ a finite different method (FDM) and a boundary integral equation method (BIEM). Using them, we simulate the scattering of these 2-D models to see if we can obtain the information of the stress loaded to the underground from variation of coda-Q. In both cases, we assumed that the scattering of seismic waves takes place due to existing cracks in the medium. We revealed that the coda-Q has relationship with the loaded stress. From the results from FDM, it turned out that the magnitude of the stress could be estimated from the coda-Q. Since the stress-dependent coda-Q shows different behavior according to the direction of the loaded stress, we think it possible to know the stress orientation, too. This tendency is derived from the occurrence of the anisotropy in the phase velocity of elastic waves, which is induced by the stress. Also from the result of BIEM, it is observed that the coda-Q varies according to the loaded stress but not depending on the orientation of cracks that might reflects stress history of the medium. We would like to conclude that the possibility of stress to be loaded to subsurface medium could be estimated using the variation of coda-Q. |
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