Yujiang Xie

Dr. Yujiang Xie is a Research Fellow Scientist at the Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin. Prior to joining UT Austin, he was a Research Fellow at the University of Southampton in the United Kingdom. Dr. Xie received his Ph.D. in Geophysics from the University of Hamburg, Germany, in 2017.

His research interests encompass theoretical and computational seismology and applied mathematics, with particular emphasis on partial differential equations, seismic wave propagation, full-waveform modeling and inversion, and high-performance scientific computing. Dr. Xie's early contributions include advancements in 3D common-reflection-surface imaging utilizing global optimization methods (Xie and Gajewski, 2018, 2019), seismic data enhancement using wavefront attributes (Xie and Gajewski, 2017), and seismic wavefront tomography grounded in seismic ray theory and wavefront attributes (Xie et al., 2018). Since 2018, Dr. Xie has concentrated efforts on finite-difference full-waveform inversion, adjoint-state methodologies, and spectral-element adjoint tomography. He developed on-the-fly second-order adjoint techniques derived through perturbation theory (Xie et al., 2021) and derived shifted Fréchet and Hessian kernel expressions for anelastic media (Xie et al., 2023). Beginning in 2024, his research expanded into anisotropic full-waveform inversion and adjoint tomography, employing multiple parameterizations and sensitivity analyses to mitigate parameter trade-offs, enhance imaging fidelity, and derive the full Hessian kernel expressions for anisotropic media (Xie et al., 2025, in prep). In 2025, Dr. Xie shifted part of his research focus toward the mathematics underlying deep learning approaches in seismology. His ongoing work aims to rigorously demonstrate the mathematical and numerical equivalence between some emerging machine-learning methods and classical methods.


Recommended books:
1. Cerveny, V. (2001). Seismic Ray Theory. Cambridge University Press.
2. Dahlen, F. A., & Tromp, J. (1998). Theoretical Global Seismology. Princeton University Press.

Selected work:
Xusong Yang, Yujiang Xie, Catherine A. Rychert, Nicholas Harmon, Saskia Goes, Andreas Rietbrock, Lloyd Lynch, and VoiLA Working Group, 2025. Seismic imaging of a basaltic Lesser Antilles slab from ancient tectonics, Nature, 640, 697-701. https://doi.org/10.1038/s41586-025-08754-0

Tianshi Liu, Kai Wang, Yujiang Xie, Bin He, Ting Lei, Nanqiao Du, Ping Tong, Yingjie Yang, Catherine A. Rychert, Nicholas Harmon, Giovanni Grasselli, Qinya Liu, 2024. Cube2sph: A Toolkit Enabling Flexible and Accurate Continental-scale Seismic Wave Simulations using the SPECFEM3D Package, Computers & Geosciences, 190, 105644. https://doi.org/10.1016/j.cageo.2024.105644

Yujiang Xie, Catherine Rychert, Nicholas Harmon, 2023. Elastic and anelastic adjoint tomography with and full Hessian kernels, Geophysical Journal International , 234, 1205-1235. https://doi.org/10.1093/gji/ggad114

Peng Yang, Dirk Gagewski and Yujiang Xie, 2023. Gaussian-weighted cross-correlation imaging condition for microseismic source localization, Geophysics, 88, 1-96. https://doi.org/10.1190/geo2022-0455.1

Nicholas Harmon, Catherine Rychert, Yujiang Xie and Bogiatzis Petros, 2022 Analytic P-to-S and S-to-P scattered wave sensitivity kernels, Geochemistry, Geophysics, Geosystems , 23, e2021GC010290. https://doi.org/10.1029/2021GC010290

Bogiatzis Petros, Catherine Rychert, Nicholas Harmon and Yujiang Xie, 2022. Fast calculation of spatial sensitivity kernels for converted waves in arbitrary heterogeneous media using graph theory, Geophysical Journal International , 230, 654-672. https://doi.org/10.1093/gji/ggac078

Yujiang Xie, Catherine Rychert, Nicholas Harmon, Qinya Liu and Dirk Gajewski, 2021. On-the-fly Full Hessian Kernel Calculations Based upon Seismic Wave Simulations, Seismological Research Letters , 92(6), 3832-3844. https://doi.org/10.1785/0220200410

Lei Li, Jingquan Tan, Dazhou Zhang, Ajay Malkoti, Ivan Abakumov and Yujiang Xie, 2021. FDwave3D: A MATLAB solver for the 3D anisotropic wave equation using the finite-difference method, Computational Geosciences, 25, 1565-1578. https://doi.org/10.1007/s10596-021-10060-3

Yujiang Xie and Dirk Gajewski, 2019. Reliability of data-driven wavefront attributes in laterally heterogeneous media, Geophysics, 84(3), O49-O62. https://doi.org/10.1190/geo2018-0382.1

Lei Li, Jingquan Tan, Yujiang Xie, Yuyang Tan, Jan Walda, Zhengguang Zhao and Dirk Gajewski, 2019. Waveform-based microseismic location using stochastic optimization algorithms: A parameter tuning workflow, Computers & Geosciences, 124, 115-127. https://doi.org/10.1016/j.cageo.2019.01.002

Yujiang Xie and Dirk Gajewski, 2018. 3-D wavefront attribute determination and conflicting dip processing, Geophysics, 83(6), V325-V343. https://doi.org/10.1190/geo2017-0792.1

Yujiang Xie and Dirk Gajewski, 2017. 5-D interpolation with wavefront attributes, Geophysical Journal International, 211, 897-919. https://doi.org/10.1093/gji/ggx334

Yujiang Xie and Gao Liu, 2015. Resolution enhancement of non-stationary seismic data using amplitude-frequency partition, Geophysical Journal International, 200, 773-778. https://doi.org/10.1093/gji/ggu401

Yujiang Xie and Gao Liu, 2014. Predicting the distribution of reservoirs by combining variable wavelet model of seismograms with wavelet edge analysis and modeling, Journal of Applied Geophysics, 101, 116-123. https://doi.org/10.1016/j.jappgeo.2013.12.005