Multiparameter two-dimensional inversion of scattered teleseismic body waves 1. Theory for oblique incidence

2001 ◽  
Vol 106 (B12) ◽  
pp. 30771-30782 ◽  
Author(s):  
M. G. Bostock ◽  
S. Rondenay ◽  
J. Shragge
Keyword(s):  
Oblique Incidence ◽  
Body Waves ◽  
Two Dimensional

Statistical properties of Rayleigh waves due to scattering by topography

1967 ◽  
Vol 57 (1) ◽  
pp. 83-90
Author(s):  
J. A. Hudson ◽  
L. Knopoff
Keyword(s):  
Surface Waves ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Forward Scattering ◽  
Statistical Properties ◽  
Body Waves ◽  
Simplified Model ◽  
Two Dimensional ◽  
Especial Reference ◽  
The Earth

abstract The two-dimensional problems of the scattering of harmonic body waves and Rayleigh waves by topographic irregularities in the surface of a simplified model of the earth are considered with especial reference to the processes of P-R, SV-R and R-R scattering. The topography is assumed to have certain statistical properties; the scattered surface waves also have describable statistical properties. The results obtained show that the maximum scattered seismic noise is in the range of wavelengths of the order of the lateral dimensions of the topography. The process SV-R is maximized over a broader band of wavelengths than the process P-R and thus the former may be more difficult to remove by selective filtering. An investigation of the process R-R shows that backscattering is much more important than forward scattering and hence topography beyond the array must be taken into account.

Absorbance and optical responsivity of two-dimensional mechanical resonators at oblique incidence

2019 ◽  
Vol 383 (23) ◽  
pp. 2755-2760
Author(s):  
Wenjing Mao ◽  
Chen Yang ◽  
Heng Lu ◽  
Jun Lu ◽  
Lin Wan ◽  
...  
Keyword(s):  
Oblique Incidence ◽  
Two Dimensional ◽  
Mechanical Resonators

Complete Two-Dimensional Principal Stress Separation by the Photoelastic Oblique Incidence Method

2006 ◽  
Vol 3-4 ◽  
pp. 229-234 ◽  
Author(s):  
Mark N. Pacey ◽  
Rachel A Tomlinson
Keyword(s):  
Principal Stress ◽  
Oblique Incidence ◽  
Normal Incidence ◽  
New Method ◽  
Two Dimensional ◽  
Principal Stresses ◽  
Isochromatic Fringe ◽  
Stress Separation

The oblique incidence method of photoelastic principal stress separation is reconsidered and presented in a form that allows the existence of negative fringe orders to be identified. The normal incidence isoclinic angle, two oblique incidence isoclinic angles and two oblique incidence isochromatic fringe orders are required for the new method. However, by allowing negative fringe orders to be identified, significant uncertainty relating to the separated principal stresses is removed and confidence in the calculated results may be improved

TRANSMISSION AND REFLECTION OF RAYLEIGH WAVES AT CORNERS

Geophysics ◽  
1958 ◽  
Vol 23 (2) ◽  
pp. 253-266 ◽  
Author(s):  
J. Cl. de Bremaecker
Keyword(s):  
Surface Wave ◽  
Rayleigh Wave ◽  
Rayleigh Waves ◽  
Body Waves ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Reflection And Transmission ◽  
Two Dimensional Model ◽  
Model Seismology ◽  
Transmission And Reflection

The methods of two dimensional model seismology were used to investigate the phenomena occurring when a Rayleigh wave is incident upon a corner whose angle is comprised between 0° and 180°. The wave bends its path only for angles between 130° and 180°. For smaller angles large and abrupt variations in reflection and transmission occur; the wave travels to the extremity of the corner and never “cuts corners”; only about 50 percent of the energy of the indicent surface wave is preserved as such, the rest goes into body waves; for a 90° corner the proportion is about 23 percent in P and 26 percent in S, with sharply preferential angles of incidence. The percentages given were found for a “plate Poisson’s ratio” of 0.17.

scholarly journals Simulation of High-Frequency Rotational Motion in a Two-Dimensional Laterally Heterogeneous Half-Space

2021 ◽  
Author(s):  
Ivan Lokmer ◽  
Varun Kumar Singla ◽  
John McCloskey
Keyword(s):  
Wave Field ◽  
Half Space ◽  
High Frequency ◽  
Body Waves ◽  
Propagation Path ◽  
Small Scale ◽  
Two Dimensional ◽  
Engineering Structures ◽  
Background Medium ◽  
Body Forces

<p>The seismic waves responsible for vibrating civil engineering structures undergo interference, focusing, scattering, and diffraction by the inhomogeneous medium encountered along the source-to-site propagation path. The subsurface heterogeneities at a site can particularly alter the local seismic wave field and amplify the ground rotations, thereby increasing the seismic hazard. The conventional techniques to carry out full wave field simulations (such as finite-difference or spectral finite element methods) at high frequencies (e.g., 15 Hz) are computationally expensive, particularly when the size of the heterogeneities is small (e.g., <100 m). This study proposes an alternative technique that is based on the first-order perturbation theory for wave propagation. In this technique, the total wave field due to a particular source is obtained as a superposition of the ‘mean’ and ‘scattered’ wave fields. Whereas the ‘mean’ wave field is the response of the background (i.e., heterogeneity-free) medium due to the given source, the ‘scattered’ wave is the response of the background medium excited by fictitious body forces. For a two-dimensional laterally heterogeneous elastic medium, these body forces can be conveniently evaluated as a function of the material properties of the heterogeneities and the mean wave field. Since the problem of simulating high-frequency rotations in a laterally heterogeneous medium reduces to that of calculating rotations in the background medium subjected to the (1) given seismic source and (2) body forces that mathematically replace the small-scale heterogeneities, the original problem can be easily solved in a computationally accurate and efficient manner by using the classical (analytical) wavenumber-integration method. The workflow is illustrated for the case of a laterally heterogenous layer embedded in a homogeneous half-space excited by plane body-waves.</p>

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