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On the Physics and Simulation of Waves at Fluid-Solid Interfaces: Application to NDT, Seismic Exploration and Earthquake Seismology by José M. Carcione (OGS, Italy)
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Page: 2 The 2D modeling algorithm
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Page: 3 2-D Equations of Motion Euler-Newton’s Equations: Constitutive Equations: Memory Variables:
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Page: 4 Scholte wave dispersion equation Relevant roots: Scholte wave Leaky Rayleigh wave
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Page: 5 Inhomogeneous waves Plane wave Elliptical polarization
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Page: 6 Reflection and transmission
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Page: 7 From a stiff ocean floor...
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Page: 8 to a soft ocean floor
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Page: 9 Numerical algorithm Two grids (domain decomposition): ocean and oceanic crust Fourier method in the horizontal direction Chebyshev method in the vertical direction Spatial derivatives Time integration 4th-order Runge-Kutta
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Page: 10 Test with the analytical solution
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Page: 11 AVA analysis Elastic case Anelastic case
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Page: 12 Rayleigh Window: Water/stainless steel
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Page: 13 Water/oceanic crust
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Page: 14 Water/plexiglass (soft bottom) No leaky Rayleigh wave
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Page: 15 Water/glass (stiff bottom)
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Page: 16 Test with analytical solution Water/plexiglass interface
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Page: 17 Test with analytical solution Water/glass interface
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Page: 18 Dispersive Scholte waves
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Page: 19 Dispersive Scholte waves Elastic caseAnelastic case North Sea. 70 m water depth. Airgun source.
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Page: 20 Ocean overlying the crust Phase velocity
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Page: 21 Ocean overlying the crust Group velocity Dissipation factor
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Page: 22 Ocean overlying the crust Attenuation coefficient Ben_Menahem and Singh (1981) Experimental data (Fig. 10.3)
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Page: 23 Ocean overlying the crust Phase/group velocities
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Page: 24 Ocean overlying the crust High-frequency case Elastic and anelastic solutions
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Page: 25 Ocean overlying the crust Low-frequency case Anelastic Elastic
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Page: 26 Sediment layer overlying the crust Low-frequency case ElasticAnelastic
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Page: 27 January 7 (2000) Earthquake
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Page: 28 Real seismograms
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Page: 29 Geological model From CRUST 5.1
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Page: 30 Synthetic seismograms
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Page: 31 The 3D modeling algorithm
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Page: 32 The Kelvin-Voigt stress-strain relation = stress components = strain components u = displacements = Lamé constants ’ ’ = damping Lamé constants
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Page: 33 Input damping parameters 0 = reference frequency Q P0 = reference P-wave quality factor Q S0 = reference S-wave quality factor
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Page: 34 The equations of motion
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Page: 35 The equations of motion v = particle velocity = density f = body forces
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Page: 36 Tests with analytical solutions Rayleigh waves -- Cagniard-de Hoop solution Pekeris (1955) solution -- unbounded media
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Page: 37 Simulation of Rayleigh waves. Model.
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Page: 38 Simulation of Rayleigh waves. Seismograms. Lossless case
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Page: 39 Simulation of Rayleigh waves. Seismograms. Lossy case
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Page: 40 Simulation of Love waves. Model.
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Page: 41 Simulation of Love waves. Seismograms. Lossless caseLossy case
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Page: 42 Conclusions Effects of anelastic attenuation Pseudospectral numerical method Inhomogeneous viscoelastic waves Differences at critical and post-critical angles Rayleigh-window effect Verified for reflection/transmission and interface waves Effective tool for seismic exploration studies, NDT and earthquake seismology
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