Optimal fourth-order staggered-grid finite-differencescheme for 3D frequency-domain viscoelastic wave modeling
Dr. Yang Li
Department of Mathematics, Harbin Institute ofTechnology, China
About the Speaker
Dr.Li is from Department of Mathematics at Harbin Institute of Technology. Hereceived his B.S. degree, M.S. degree and Ph.D. degree in Mathematics from the HarbinInstitute of Technology in 2009, 2011 and 2016 respectively. From September2012 to September 2014, he worked as a joint Ph.D. student in Institut des Sciences dela Terre(Institute of Earth Science) at Université Joseph Fourier, France.
The keyidea in this talk is about investigating an optimal fourth-order staggered-gridfinite-difference scheme for 3D frequency-domain viscoelastic wave modeling.The optimal finite-difference coefficients and the mass weighting coefficientsare obtained by minimizing the misfit between the normalized phase velocitiesand the unity. An iterative damped least-squares method, theLevenberg–Marquardt algorithm, is utilized for the optimization. Dispersionanalysis shows that only 3.7 grid-points per minimum shear wavelength arerequired to keep the error of the group velocities below 1%. A paralleliterative method named CARP-CG is used to solve the large ill-conditionedlinear system for the frequency-domain modeling. Validations are conducted withrespect to both the analytic viscoacoustic and viscoelastic solutions.