A frequency-domain spectral-infinite-element method for simulations of seismic wave propagation

Abstract:

Time-domain methods based on explicit schemes are most commonly used to solve seismic wave propagation problems. The spectral-element method is well suited to explicit time schemes, providing accuracy and efficiency due to higher-order elements and a diagonal mass matrix. However, explicit time schemes are unsuitable for long-duration simulation due to the conditional stability and overall high computational cost. We develop a frequency-domain spectral-infinite-element method to solve seismic wave propagation problems involving long duration for a wide range of scales. Infinite elements are used to accommodate full gravity in global simulations. The computational cost for the frequency-domain simulations is higher per frequency step. Still, each frequency step is independent, leading to a massively parallel implementation. Furthermore, the method is unconditionally stable. We demonstrate various examples for both local- and global-scale seismic wave propagation applications.