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1995 Fiscal Year Final Research Report Summary

Waveform inversion for 3-D Earth structure using a new inverse algorithm

Research Project

Project/Area Number 06640542
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 固体地球物理学
Research InstitutionThe University of Tokyo

Principal Investigator

GELLER Robert J  The University of Tokyo Graduate School of Science Associate Professor, 大学院・理学系研究科, 助教授 (40170154)

Project Period (FY) 1994 – 1995
KeywordsEarth structure / inversion / synthetic seismograms / numerical computation
Research Abstract

The purpose of this research project is inverting 3-D earth structure with high accuracy and high resolution using digital seismic waveforms. We have developed an efficient method (Direct Solution Method) which computes synthetic seismograms and their partial derivatives efficiently and a new inverse algorithm. In this research project, we have planed to invert 3-D earth structure using broadband seismic waveforms using these research results. However to invert earth structure with high accuracy, we have developed more accurate and efficient computational methods and softwares. By the research results of this project, the accuracy an the efficiency of computation of synthetic seismograms are greatly improved.
We will list chief research results below.
1.We have computed 4-5000s highly accurate DSM synthetic seismograms using the Direct Solution Method. We showed that we can compute highly accurate synthetics if we use DSM.
2.We have derived a general criterion which should be satisfied by numerically accurate op erators (modified operators), and derived DSM modified operators satisfying this criterion for arbitrarily heterogeneous media without increasing their bandwidth.
3.We have derived modified operators for spherical coordinate problems which will be used for inversions. We have developed softwares using these modified operators for sphericall symmetric and 3-D heterogeneous earth structure. By these results, we came to be able to compute highly accurate 20-5000s P-SV synthetic seismograms in 10 minutes (on SPARC 20). We came to be able to compute highly accurate synthetics for 3-D heterogeneous structure.
4.We have developed theory and softwares which uses analytical solutions as a trial function which are used for expansion of the displacement field.

  • Research Products

    (16 results)

All Other

All Publications (16 results)

  • [Publications] 原 辰彦: "波形インバージョン" 地学雑誌. 104. 972-983 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] R.J.Geller: "A new method for computing highly acourate DSM synthetic seismograms" Geophys.J.Int.123. 449-470 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 原 辰彦: "Direct Solution Methodによる地球内部3次元構造の決定" 地震. 47. 405-409 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] R.J.Geller: "DSM synthetic seismograms using analytical trial function : plane-layered,isotropic,case" Geophys.J.Int.120. 163-172 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] P.R.Cummins: "DSM complete synthetic seismograms : P-SV,Spherically symmetric,case" Geophys.Res.Lett.21. 1663-1666 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hara: "Anomalously large near-field Rayleigh waves excited by the 1992 Landars,California earthquake" Bull.seism.Soc.Am.84. 751-760 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hara: "The geophysical origin of long wavelength lateral heterogeneity at dpets of 300-400 km" Geophys.Res.Lett.21. 907-910 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] P.R.Cummins: "DSM complete synthetic seismograms : SH,spherically symmetric,case" Geophys.Res.Lett.21. 533-536 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hara, R.J.Geller: "Waveform inversion for Earth structure" J.Geography. 104. 972-983 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] R.J.Geller & N.Takeuchi: "A new method for computing highly accurate DSM synthetic seismograms" Geophys.J.Int.123. 449-470 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hara, R.J.Geller: "Determining 3-D earth structure using the Direct Solution Method" J.Seism.Soc.Japan. 47. 405-409 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] R.J.Geller & T.Hatori: "DSM synthetic seismograms using analytic trial functions : plane-layred, isotropic, case" Geophys.J.Int.120. 163-172 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] P.R.Cummins, R.J.Geller & N.Takeuchi: "DSM complete synthetic seismograms : P-SV,spherically symmetric, case" Geophys.Res.Lett.21. 1663-1666 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hara & R.J.Geller: "Anomalously large near-field Rayleigh waves excited by the 1992 Landers, California earthquake" Bull.seism.Soc.Am. 84. 751-760 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hara & R.J.Geller: "The geological origin of long wavelength lateral heterogeneity at depths of 300-400km" Geophys.Res.Lett.21. 907-910 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] P.R.Cummins, R.J.Geller, T.Hatori & N.Takeuchi: "DSM complete synthetic seismograms : SH,spherically symmetric, case" Geophys.Res.Lett.21. 533-536 (1994)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-03-09  

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