Numerical modeling of elastic wave scattering by near-surface heterogeneities
A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated using elastic finite difference for several earth models with different nearsurfa...
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| Format: | Technical Report |
| Language: | en_US |
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Massachusetts Institute of Technology. Earth Resources Laboratory
2014
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| Online Access: | http://hdl.handle.net/1721.1/90510 |
| _version_ | 1826216889792069632 |
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| author | Al Muhaidib, Abdulaziz Toksoz, M. Nafi |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Al Muhaidib, Abdulaziz Toksoz, M. Nafi |
| author_sort | Al Muhaidib, Abdulaziz |
| collection | MIT |
| description | A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated using elastic finite difference for several earth models with different nearsurface characteristics. The near-surface scattered wavefield is modeled by separating the incident wavefield from the total wavefield by means of a perturbation method. We show that the scattered field is equivalent to the radiation field of an equivalent elastic source excited at the scatterer locations. The scattered waves consist mostly of body waves scattered to surface waves and are, generally, as large as, or larger than, the reflections. The results indicate that the scattered energy depends strongly on the properties of the shallow scatterers and increases with increasing impedance contrast, increasing size of the scatterers relative to the incident wavelength, and decreasing depth of the scatterers. Also, sources deployed at depth generate weaker surface waves, whereas deep receivers record weaker surface and scattered body-to-surface waves. |
| first_indexed | 2024-09-23T16:55:04Z |
| format | Technical Report |
| id | mit-1721.1/90510 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:55:04Z |
| publishDate | 2014 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/905102019-04-10T18:31:48Z Numerical modeling of elastic wave scattering by near-surface heterogeneities Al Muhaidib, Abdulaziz Toksoz, M. Nafi Massachusetts Institute of Technology. Earth Resources Laboratory Modeling Scattering A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated using elastic finite difference for several earth models with different nearsurface characteristics. The near-surface scattered wavefield is modeled by separating the incident wavefield from the total wavefield by means of a perturbation method. We show that the scattered field is equivalent to the radiation field of an equivalent elastic source excited at the scatterer locations. The scattered waves consist mostly of body waves scattered to surface waves and are, generally, as large as, or larger than, the reflections. The results indicate that the scattered energy depends strongly on the properties of the shallow scatterers and increases with increasing impedance contrast, increasing size of the scatterers relative to the incident wavelength, and decreasing depth of the scatterers. Also, sources deployed at depth generate weaker surface waves, whereas deep receivers record weaker surface and scattered body-to-surface waves. Massachusetts Institute of Technology. Earth Resources Laboratory (Founding Members) 2014-10-02T12:54:46Z 2014-10-02T12:54:46Z 2013 Technical Report http://hdl.handle.net/1721.1/90510 en_US Earth Resources Laboratory Industry Consortia Annual Report;2013-25 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Modeling Scattering Al Muhaidib, Abdulaziz Toksoz, M. Nafi Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title | Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title_full | Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title_fullStr | Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title_full_unstemmed | Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title_short | Numerical modeling of elastic wave scattering by near-surface heterogeneities |
| title_sort | numerical modeling of elastic wave scattering by near surface heterogeneities |
| topic | Modeling Scattering |
| url | http://hdl.handle.net/1721.1/90510 |
| work_keys_str_mv | AT almuhaidibabdulaziz numericalmodelingofelasticwavescatteringbynearsurfaceheterogeneities AT toksozmnafi numericalmodelingofelasticwavescatteringbynearsurfaceheterogeneities |