PyGRT: An Efficient and Integrated Python Package for Computing Synthetic Seismograms in a Layered Half-Space Model

Abstract Synthetic seismograms play a crucial role in understanding Earth’s internal structure and focal mechanisms. Although established methods remain fundamental, advancements in computational tools and optimizations are crucial for improving stability, efficiency, and accessibility in modern seismic modeling. Here, we introduce PyGRT, an open-source Python package designed to calculate synthetic seismograms for a point source in a layered half-space model. Built on the generalized reflection-transmission matrix method and the discrete wavenumber method, PyGRT integrates the peak-trough averaging method and Filon’s integration method to handle diverse source–receiver distributions. To optimize performance, PyGRT uses C for its core computational tasks, accelerated with OpenMP for parallel processing, whereas Python provides a user-friendly interface. This dual-language approach combines efficiency with ease of use, offering a flexible and extensible framework for seismic modeling. The modular design includes both low-level C and high-level Python interfaces, enabling high-performance computing, easy customization, and streamlined data processing. PyGRT outperforms traditional tools in stability for high-frequency calculations, computational speed, and accessibility. It serves as a practical and versatile resource, providing both researchers and beginners with a robust tool for seismic-wave simulation and theoretical exploration.