Numerical simulation of seismic wavefield based on modified EAL boundary condition
In the process of seismic wavefield simulation,artificial truncated boundaries generate spurious reflection,reducing the accuracy of seismic wavefield simulation.The Perfectly Matched Layer(PML)absorbing boundary condition is an effective means of eliminating spurious boundary reflections,but this method is computationally expensive and difficult to implement.In addition,it is instability in some anisotropic media.Effective Absorbing Layer(EAL)boundary condition is an absorbing boundary condition derived by simplifying the damping terms of PML absorbing boundary conditions.The absorption term of EAL is applied only to the time derivative terms of the wave equation.Therefore,the EAL boundary condition costs smaller computation than PML and facilitates parallel implementation.The application of the EAL boundary condition can improve computational efficiency and reduce memory consumption while ensuring the accuracy of full-waveform inversion and reverse-time migration.In this paper,we improve the EAL boundary condition by introducing the velocity damping term and constructing the damping term with the Gaussian spatial weighting function.The forward modeling results show that the improved EAL boundary condition can effectively boost the absorption effect without increasing the computational burden and memory consumption.It is suitable for complex and anisotropic media.In particular,the EAL boundary condition has higher stability in anisotropic models than the PML absorbing boundary condition.
Absorbing boundary conditionsTime-space finite differenceWave equationAnisotropic medium
NETL
NSTL
万方数据
维普
