Synthetic Seismograms in Heterogeneous Elastic Waveguides and Applications in Investigating LG-Wave Propagation

1998 ◽  
Author(s):  
R. S. Wu ◽  
S. Jin ◽  
X. B. Xie ◽  
T. Lay
Keyword(s):  
Wave Propagation ◽  
Synthetic Seismograms ◽  
Lg Wave ◽  
Elastic Waveguides

scholarly journals Lg wave propagation in the area around Japan: observations and simulations

2014 ◽  
Vol 1 (1) ◽  
pp. 10 ◽  
Author(s):  
Takashi Furumura ◽  
Tae-Kyung Hong ◽  
Brian LN Kennett
Keyword(s):  
Wave Propagation ◽  
Lg Wave

Boundary conditions for the numerical solution of wave propagation problems

Geophysics ◽  
1978 ◽  
Vol 43 (6) ◽  
pp. 1099-1110 ◽  
Author(s):  
Albert C. Reynolds
Keyword(s):  
Wave Propagation ◽  
Reflection Coefficient ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Numerical Solution ◽  
Neumann Boundary ◽  
Synthetic Seismograms ◽  
Neumann Boundary Conditions ◽  
Numerical Calculations ◽  
Reflection Coefficients

Many finite difference models in use for generating synthetic seismograms produce unwanted reflections from the edges of the model due to the use of Dirichlet or Neumann boundary conditions. In this paper we develop boundary conditions which greatly reduce this edge reflection. A reflection coefficient analysis is given which indicates that, for the specified boundary conditions, smaller reflection coefficients than those obtained for Dirichlet or Neumann boundary conditions are obtained. Numerical calculations support this conclusion.

Generation of Synthetic Seismograms Using Linear Systems Theory

1971 ◽  
Vol 8 (11) ◽  
pp. 1409-1422 ◽  
Author(s):  
O. G. Jensen ◽  
R. M. Ellis
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Systems Theory ◽  
Linear Systems ◽  
Time Domain ◽  
Synthetic Seismograms ◽  
Elastic Wave Propagation ◽  
Arbitrary Angle ◽  
Teleseismic Events

The linear systems theory for elastic wave propagation in a multilayered crust has been extended to time domain solutions. Attenuation is specifically included. This direct time domain approach allows the computation of synthetic seismograms for P or SV waveforms incident at an arbitrary angle at the base of the crustal section. To demonstrate the utility of the technique, seismograms are computed for various conditions and comparisons made with teleseismic events recorded in central Alberta.

Wave Propagation Theory and Synthetic Seismograms

1991 ◽  
Vol 29 (S2) ◽  
pp. 662-670 ◽  
Author(s):  
CHARLES A. LANGSTON
Keyword(s):  
Wave Propagation ◽  
Synthetic Seismograms ◽  
Propagation Theory

Lg wave propagation and attenuation characteristics of the NW Himalaya

2021 ◽  
Author(s):  
Kaushik Kumar Pradhan ◽  
Supriyo Mitra
Keyword(s):  
Wave Propagation ◽  
Quality Factor ◽  
Spectral Ratio ◽  
Spectral Amplitude ◽  
Nw Himalaya ◽  
Jammu And Kashmir ◽  
Waveform Data ◽  
Ground Shaking ◽  
Lg Wave ◽  
Attenuation Characteristics

<p>Lg waves are formed by the superposition of shear waves trapped within the crustal waveguide and are the most destructive at regional distances. Excitation of Lg waves, its propagation and lateral variability determine the intensity of ground shaking from regional earthquakes. Spatial decay of spectral amplitude of Lg waves have been used to quantify the attenuation characteristics of the crust. In this study we use regional waveform data from the Jammu and Kashmir Seismological NETwork (JAKSNET) to study Lg wave propagation across the Indian Peninsula, Himalaya, Tibetan Plateau and Hindu Kush regions. We compute Lg/Sn wave ratio to distinguish regions with efficient Lg propagation from those with Lg blockage. These results are categorised using earthquake magnitude and depth to study Lg wave excitation and propagation across these varying geological terrains. We further use the two-station method to study Lg wave quality factor and its frequency dependence for the NW Himalaya. Seismograms recorded at two stations of the network, which are aligned within 15 degrees of the event, are used for analysis. The spectral ratio of Lg wave amplitude recorded at the two stations will be used to estimate the Q (quality factor) as a function of frequency. This will provide Q<sub>0</sub> along all inter-station paths, which will then be combined to form Q<sub>0</sub> tomography maps for the region. Checkerboard tests will be performed to estimate the resolution of the tomographic maps and accordingly the results will be interpreted.</p>

Study of Surface Effects on LG Wave Propagation in Heterogeneous Crusts by a GS-BE Hybrid Method

1998 ◽  
Author(s):  
R. S. Wu ◽  
T. Lay ◽  
X. B. Xie ◽  
L. Fu ◽  
S. Jin
Keyword(s):  
Wave Propagation ◽  
Hybrid Method ◽  
Surface Effects ◽  
Lg Wave

Numerical simulations of wave propagation in heterogeneous wave guides with implications for regional wave propagation and the nature of lithospheric heterogeneity

1996 ◽  
Vol 86 (4) ◽  
pp. 1200-1206
Author(s):  
Gregory S. Wagner
Keyword(s):  
Wave Propagation ◽  
Scattered Wave ◽  
Wave Guide ◽  
Subsurface Structure ◽  
Forward Scatter ◽  
Wave Fields ◽  
Wave Guides ◽  
Statistical Sense ◽  
Lg Wave ◽  
Wave Trains

Abstract I present results from elastic finite-difference simulations of regional wave propagation conducted in an effort to characterize, in a statistical sense, the nature of lithospheric heterogeneities required to generate scattered wave fields with characteristics consistent with those observed in regional array data. In particular, regional P, S, and Lg wave trains that are comprised not of the occasional coherent deterministic phase emersed in randomly scattered coda, but of a continuous succession of coherent forward-scattered arrivals. My modeling suggests that lithospheric heterogeneities should be parameterized using spatially anisotropic correlation functions. Models containing spatially isotropic heterogeneities inhibit the extent to which energy is forward scattered and trapped in the crustal wave guide and, consequently, produce regional wave fields whose characteristics are inconsistent with array observations. Models containing spatially anisotropic heterogeneities—which preferentially forward scatter energy that is subsequently trapped in the crustal wave guide—produce wave fields whose characteristics are consistent with regional array observations and provide intuitively appealing representations of subsurface structure.

Lg Wave Propagation in Eurasia

1981 ◽  
pp. 421-451 ◽  
Author(s):  
Svein Mykkeltveit ◽  
Eystein S. Husebye
Keyword(s):  
Wave Propagation ◽  
Lg Wave
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