Self-adaptive physics-driven deep learning for seismic wave modeling in complex topography

Solving for the scattered wavefield is a key scientific problem in the field of seismology and earthquake engineering. Physics-informed neural networks (PINNs) developed in recent years have great potential in possibly increasing the flexibility and efficacy of seismic modeling and inversion. Inspired by self-adaptive physics-informed neural networks (SA-PINNs), we introduce a framework for modeling seismic waves in complex topography The relevant theoretical model construction was performed using the one-dimensional (1D) wave equation as an example. Using SA-PINNs and combining them with sparse initial wavefield data formed by the spectral element method (SEM), we carry out a numerical simulation of two-dimensional (2D) SH wave propagation to realize typical cases such as infinite/semi-infinite domain and arc-shaped canyon/hill topography. For complex scattered wavefields, a sequential learning method with time-domain decomposition was introduced in SA-PINNs to improve the scalability and solution accuracy of the network. The accuracy and reliability of the proposed method to simulate wave propagation in complex topography were verified by comparing the displacement seismograms calculated by the SA-PINNs method with those calculated by the SEM. The results show that the SA-PINNs have the advantage of gridless and fine-grained simulation and can realize numerical simulation conditions, such as free surface and side-boundary wavefield transmission.