Seismic wave numerical modeling of the combined optimal difference coefficient method of variable staggered grid

2018 ◽  
Author(s):  
Li Shizhong ◽  
Sun Chengyu ◽  
Wu Dunshi ◽  
Qiu Yue ◽  
Lu Yawei
Keyword(s):  
Numerical Modeling ◽  
Seismic Wave ◽  
Staggered Grid ◽  
Coefficient Method

Mimetic seismic wave modeling including topography on deformed staggered grids

Geophysics ◽  
2014 ◽  
Vol 79 (3) ◽  
pp. T125-T141 ◽  
Author(s):  
Josep de la Puente ◽  
Miguel Ferrer ◽  
Mauricio Hanzich ◽  
José E. Castillo ◽  
José M. Cela
Keyword(s):  
Finite Difference ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Numerical Solutions ◽  
Surface Condition ◽  
Finite Difference Methods ◽  
Staggered Grid ◽  
Grid Deformation ◽  
Large Dispersion ◽  
Difference Methods

Finite-difference methods for modeling seismic waves are known to be inaccurate when including a realistic topography, due to the large dispersion errors that appear in the modelled surface waves and the scattering introduced by the staircase approximation to the topography. As a consequence, alternatives to finite-difference methods have been proposed to circumvent these issues. We present a new numerical scheme for 3D elastic wave propagation in the presence of strong topography. This finite-difference scheme is based upon a staggered grid of the Lebedev type, or fully staggered grid (FSG). It uses a grid deformation strategy to make a regular Cartesian grid conform to a topographic surface. In addition, the scheme uses a mimetic approach to accurately solve the free-surface condition and hence allows for a less restrictive grid spacing criterion in the computations. The scheme can use high-order operators for the spatial derivatives and obtain low-dispersion results with as few as six points per minimum wavelength. A series of tests in 2D and 3D scenarios, in which our results are compared to analytical and numerical solutions obtained with other numerical approaches, validate the accuracy of our scheme. The resulting FSG mimetic scheme allows for accurate and efficient seismic wave modelling in the presence of very rough topographies with the advantage of using a structured staggered grid.

Numerical Modeling of Seismic Wave Propagation

2012 ◽  
Author(s):  
Johan O. A. Robertsson ◽  
Joakim O. Blanch ◽  
Kurt Nihei ◽  
Jeroen Tromp
Keyword(s):  
Numerical Modeling ◽  
Wave Propagation ◽  
Seismic Wave ◽  
Seismic Wave Propagation

The Effects of 3D Electrical Anisotropy on Magnetotelluric Responses: Synthetic Case Studies

2018 ◽  
Vol 23 (1) ◽  
pp. 61-75
Author(s):  
Wenxin Kong ◽  
Changhong Lin ◽  
Handong Tan ◽  
Miao Peng ◽  
Tuo Tong ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Finite Difference Method ◽  
Apparent Resistivity ◽  
Electrical Anisotropy ◽  
Staggered Grid ◽  
Qualitative And Quantitative ◽  
Resistivity Tensor ◽  
Quantitative Analyses ◽  
Prism Model ◽  
Euler’S Angles

Using the staggered-grid finite difference method, a numerical modeling algorithm for a 3D arbitrary anisotropic Earth is implemented based on magnetotelluric (MT) theory. After the validation of this algorithm and comparison with predecessors, it was applied to several qualitative and quantitative analyses containing electrical anisotropy and a simple 3D prism model. It was found that anisotropic parameters for ρ 1 , ρ 2 , and ρ 3 play almost the same role in affecting 3D MT responses as in 1D and 2D without considering three Euler's angles α S , α D , and α L . Significant differences appear between the off-diagonal components of the apparent resistivity tensor and also between the diagonal components in their values and distributing features under the influence of 3D anisotropy, which in turn help to identify whether the MT data are generated from 3D anisotropic earth. Considering the deflecting effects arising from the inconsistency between the anisotropy axes and the measuring axes, some strategies are also provided to estimate the deflecting angles associated with anisotropy strike α S or dip α D , which may be used as initial values for the 3D anisotropy inversion. [Figure: see text]

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