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Full waveform moment tensor inversion by reciprocal finite difference Green’s function
Earth, Planets and Space volume 54, pages 715–720 (2002)
Abstract
We study two important aspects of the waveform moment tensor inversion for the shallow earthquakes in the subduction region: the effect of the intense lateral inhomogeneity in the structure, and the strategy to invert the waveform data for the focal mechanisms. For the first aspect, using a “forward” finite difference modeling, we demonstrate that the effect of the inhomogeneity is quite large on the surface waves with a period of about 20s, and the current knowledge on the subduction region structure is practically effective in reproducing the characteristics in the observed waveforms. For the second aspect, we develop a “reciprocal” moment tensor inversion method that can generate the Green’s functions for a large quantity of source locations (19,200 in this study) in a realistic inhomogeneous structure by only three finite difference calculations per a single station. The inversion with a grid search scheme result in a reasonable source location, moment tensor and fit of the waveforms using data from only two stations. The constraint on the epicenter in the “transverse” direction is found to be somewhat weak in the case of single-station inversions, but the two-station inversion improves the constraint.
References
Delouis, B. and D. Legrand, Focal mechanism determination and identification of the fault plane of earthquakes using only one or two near-source seismic recordings, Bull. Seism. Soc. Am., 89, 1558–1574, 1999.
Dziewonski, A. M. and J. H. Woodhouse, Studies of the seismic source using normal mode theory, Proc. Enrico Fermi Sch. Phys., 85, 45–137, 1983.
Fukuyama, E., M. Ishida, D. S. Dreger, and H. Kawai, Automated seismic moment tensor determination by using on-line broadband seismic waveforms, Zisin (J. Seism. Soc. Japan, 2nd series), 51, 149–156, 1998 (in Japanese with English abstract).
Furumura, T. and H. Takenaka, 2.5-D modelling of elastic waves using the pseudospectral method, Geophys. J. Int., 124, 820–832, 1996.
Hino, R., T. Kanazawa, and A. Hasegawa, Interplate seismic activity near the northern Japan Trench deduced from ocean bottom and land-based seismic observations, Phys. Earth Planet. Inter., 93, 37–52, 1996.
Kawakatsu, H., Automated near-realtime CMT inversion, Geophys. Res. Lett., 22, 2569–2572, 1995.
Kikuchi, M. and H. Kanamori, Inversion of complex body waves—III, Bull. Seism. Soc. Am., 81, 2335–2350, 1991.
Mori, J. and K. Shimazaki, Inversion of intermediate-period Rayleigh waves for source characteristics of the 1968 Tokachi-Oki earthquake, J. Geophys. Res., 90, 11374–11382, 1985.
Murauchi, S. and W. Ludwig, Crustal structure of the Japan trench: the effect of subduction of ocean crust, in Scientific Party, in Initial Reports of the Deep Sea Drilling Project, 56, 57, Pt. 1, U.S. Govt. Printing Office, Washington, 1980.
Nakayama, W. and M. Takeo, Slip history of the 1994 Sanriku-Haruka-Oki, Japan, earthquake deduced from strong-motion data, Bull. Seism. Soc. Am., 87, 918–931, 1997.
Okamoto, T., Location of shallow subduction zone earthquake inferred from teleseismic body waveform, Bull. Seism. Soc. Am., 84, 264–268, 1994a.
Okamoto, T., Teleseismic synthetics obtained from 3-D calculations in 2-D media, Geophys. J. Int., 118, 613–622, 1994b.
Pasyanos, M. E., D. S. Dreger, and B. Romanowicz, Toward Real-Time Estimation of Regional Moment Tensors, Bull. Seism. Soc. Am., 86, 1255–1269, 1996.
Sipkin, S. A., Rapid determination of global moment-tensor solutions, Geophys. Res. Lett., 21, 1667–1670, 1994.
Suyehiro, K., T. Kanazawa, and H. Shimamura, Air gun-ocean bottom seismograph seismic structure across the Japan trench area, in Initial Reports of the Deep Sea Drilling Project, edited by H. Kagami, D. E. Karig, W. T. Coulbourn et al., 87, U.S. Govt. Printing Office, Washington, 1980.
Tanimoto, T., Modelling curved surface wave paths: membrane surface wave synthetics, Geophys. J. Int., 102, 89–100, 1990.
Thio, H. K. and H. Kanamori, Moment tensor inversions for local earthquakes using surface waves recorded at TERRAscope, Bull. Seism. Soc. Am., 85, 1021–1038, 1995.
Umino, N., A. Hasegawa, and T. Matsuzawa, sP depth phase at small epicentral distances and estimated subducting plate boundary, Geophys. J. Int., 120, 356–366, 1995.
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Okamoto, T. Full waveform moment tensor inversion by reciprocal finite difference Green’s function. Earth Planet Sp 54, 715–720 (2002). https://doi.org/10.1186/BF03351723
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DOI: https://doi.org/10.1186/BF03351723