Staggered‐Grid High‐Order Finite‐Difference Method in Elastic Wave Simulation with Variable Grids and Local Time‐Steps

Abstract Accuracy and efficiency are most urgent problems in elastic wave simulation. Staggered‐grid is an effective method to improve the accuracy with high efficiency. By the combination of variable grids and locally variable time‐steps, a staggered‐grid high‐order finite‐difference method with oddly arbitrarily variable spatial grids and arbitrarily variable local time‐steps is presented. The numerical results show that the simulation accuracy and efficiency are increased effectively by avoiding oversampling both in space and time domain. Additionally, compared with the traditional method, this modeling method has advantages in seismic wave simulation in the medium with fractures, caves and complicated structures. It can describe such medium in details, and has high accuracy and efficiency.