Forward modeling method and application of teleseismic wavefield

Abstract

Seismic wavefield numerical simulation is an important base for crust-mantle structure imaging and deep exploration. The classical teleseismic wavefield simulation methods, including analytical method, semi-analytical method and numerical method, are mainly based on one-dimensional Earth model. These algorithms can efficiently calculate the synthetic seismogram, but the lateral heterogeneity of the medium is not being incorporated. With the improvement of computer performance, numerical simulation methods for three-dimensional seismic have been developed rapidly, and have been widely used in both local and regional seismic wave simulations. But due to the limitation of computing resources, the implementation of high frequency seismic wavefield numerical simulation based on global scale is still a great challenge. In recent years, hybrid numerical simulation methods of teleseismic wavefield have been developed, in which the target simulation region is decomposed into two scales (global scale and local scale). In global scale, high-frequency synthetic seismogram is calculated through fast algorithm based on one-dimensional earth model assumption. With injection method, three-dimensional numerical methods (spectral element method, finite difference method, etc.) are used to simulate the propagation of seismic wave in three-dimensional heterogeneous medium in local target scale, to achieve the balance between efficiency and accuracy. With the development of dense array observation, scientific research puts forward higher requirements for the resolution of underground structure imaging. Accurate and efficient hybrid simulation method of seismic wavefield will play an important role in the field of high-resolution seismic imaging. In this paper, we systematically summarize one-dimensional simulation methods of teleseismic wavefield numerical simulations, as well as the principle and application of hybrid numerical simulation methods of teleseismic wavefield.

Keywords

• teleseismic wavefield simulation
• crust-mantle structure imaging
• synthetic seismograms
• hybrid method