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| Format: | Artículo científico |
| Language: | en |
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Universidad Nacional Autónoma de México
2005
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| Online Access: | https://www.redalyc.org/articulo.oa?id=56844201 |
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Table of Contents:
- Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods José M. Carcione Hans B. Helle Géza Seriani Milton P. Plasencia Linares Ciencias de la Tierra modeling Seismogram earthquake attenuation Scholte waves Using an improved global pseudospectral modeling algorithm we synthesize seismograms generated by oceanic and continentalearthquakes. Attention is given to attenuation, to explicit modeling of boundary conditions at the ocean-bottom interface,simulation of the Rayleigh window and interface-wave propagation. The algorithm is based on Fourier and Chebyshev differentialoperators and a domain-decomposition technique - one grid for the fluid and another grid for the solid. Wave propagation in theoceanic and continent crusts and mantle is modeled by using a viscoelastic stress-strain relation based on memory variables.The main physical phenomena associated with an ocean-crust system are modeled, including Scholte waves, leaking Rayleighwaves, dispersive modes, and the Rayleigh-window phenomenon due to a minimum in the reflection coefficient of the oceanbottom, which has not been simulated with direct methods. In particular, we model Rayleigh modes (mainly the M11 mode), andcoupled Rayleigh-Scholte waves, for which the dispersion relation is solved in simple cases. Also, we model the effects of randominhomogeneities in the crust and mantle by using a von Kármán autocovariance probability function, which simulates scattering-Q-effects.The 2-D modeling code allows general material variability, and a complete and accurate characterization of the seismicresponse of oceanic and continental earthquakes. A synthetic seismogram for an earthquake in the South Atlantic region is provided. 2005 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56844201 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.2 Vol.44