TomoATT: An open-source package for Eikonal equation-based adjoint-state traveltime tomography for seismic velocity and azimuthal anisotropy

TL;DR

TomoATT is an open-source software package that utilizes adjoint-state traveltime tomography with Eikonal equation modeling to accurately image seismic velocity and anisotropy, demonstrating high performance and reliability in real-world applications.

Contribution

It introduces a user-friendly, efficient open-source tool that integrates advanced modeling, regularization, and parallelization for seismic traveltime tomography, validated through synthetic and real data.

Findings

Accurately recovers synthetic models

Consistent imaging with regional tectonics

Completes inversion within 2 hours using 64 processors

Abstract

TomoATT is an open-source software package, aiming at determining seismic velocity and azimuthal anisotropy based on adjoint-state traveltime tomography methods. Key features of TomoATT include Eikonal equation modeling, adjoint-state method, sensitivity kernel regularization, and multi-level parallelization. Through several toy experiments, we demonstrate TomoATT's capability in accurate forward modeling, handling multipathing phenomenon, delivering reliable tomographic results, and achieving high-performance parallelization. Additionally, TomoATT is benchmarked with a synthetic experiment and two real-data applications in central California near Parkfield and Thailand. The successful recovery of the synthetic model, along with the imaging results that are consistent with previous studies and regional tectonics, verifies the effectiveness of TomoATT. Each inversion starts with only three simple input files (about model, data, and parameters) and completes within 2 hours using 64 processors. Overall, TomoATT offers an efficient and user-friendly tool for regional and teleseismic traveltime tomography, empowering researchers to image subsurface structures and deepen our understanding of the Earth's interior.