Lowrank seismic wave extrapolation on a staggered grid

Published as Geophysics, 79, no. 3, T157-T168, (2014)

Lowrank seismic wave extrapolation on a staggered grid

Gang Fang, Sergey Fomel, Qizhen Du, and Jingwei Hu
School of Geosciences
China University of Petroleum (East China)
Qingdao, Shandong 266580, China
fangg.geo@gmail.com; gangfang@utexas.edu
Bureau of Economic Geology,
John A. and Katherine G. Jackson School of Geosciences
The University of Texas at Austin
University Station, Box X
Austin, TX 78713-8972, USA
sergey.fomel@beg.utexas.edu
School of Geosciences
China University of Petroleum (East China)
Qingdao, Shandong 266580, China
multicomponent@163.com; duqizhen@upc.edu.cn
Institute for Computational Engineering and Sciences (ICES)
The University of Texas at Austin
201 East 24th St, Stop C0200, Austin, TX 78712, USA
hu@ices.utexas.edu

Abstract:

We propose a new spectral method and a new finite-difference method for seismic wave extrapolation in time. Using staggered temporal and spatial grids, we derive a wave extrapolation operator using a lowrank decomposition for a first-order system of wave equations and design the corresponding finite-difference scheme. The proposed methods extend previously proposed lowrank and lowrank finite-difference wave extrapolation methods from the cases of constant density to those of variable density. Dispersion analysis demonstrates that the proposed methods have high accuracy for a wide wavenumber range and significantly reduce the numerical dispersion. The method of manufactured solutions coupled with mesh refinement is used to verify each method and to compare numerical errors. 2-D synthetic examples demonstrate that the proposed method is highly accurate and stable. The proposed methods can be used for seismic modeling or reverse time migration.

Lowrank seismic wave extrapolation on a staggered grid