@article{0e1eefecc44247ab8cc6c51222637c29,
title = "Balancing unevenly distributed data in seismic tomography: A global adjoint tomography example",
abstract = "The uneven distribution of earthquakes and stations in seismic tomography leads to slower convergence of nonlinear inversions and spatial bias in inversion results. Including dense regional arrays, such as USArray or Hi-Net, in global tomography causes severe convergence and spatial bias problems, against which conventional pre-conditioning schemes are ineffective. To save computational cost and reduce model bias, we propose a new strategy based on a geographical weighting of sources and receivers. Unlike approaches based on ray density or the Voronoi tessellation, this method scales to large full-waveform inversion problems and avoids instabilities at the edges of dense receiver or source clusters. We validate our strategy using a 2-D global waveform inversion test and show that the new weighting scheme leads to a nearly twofold reduction in model error and much faster convergence relative to a conventionally pre-conditioned inversion.We implement this geographical weighting strategy for global adjoint tomography.",
keywords = "Computational seismology, Inverse theory, Seismic tomography, Theoretical seismology, Waveform inversion",
author = "Youyi Ruan and Wenjie Lei and Ryan Modrak and Rldvan {\"O}rsvuran and Ebru Bozdaǧ and Jeroen Tromp",
note = "Funding Information: We gratefully acknowledge editor Lapo Boschi, David Al-Attar, and two anonymous reviewers for their constructive reviews which improved the manuscript. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF), which is a DOE Office of Science User Facility supported under contract DE-AC05-00OR22725. This research was supported by the U.S. National Science Foundation under grant 1644826. YR was also supported by the Fundamental Research Fund for Central Universities under grant number 0206-14380080. The 2-D numerical experiments were performed on {\textquoteleft}Tiger{\textquoteright} at the Princeton Institute for Computational Science and Engineering, and the 42-event pilot tests were performed on the Cray XK7 supercomputer {\textquoteleft}Titan{\textquoteright} at the OLCF. Funding Information: We gratefully acknowledge editor Lapo Boschi, David Al-Attar, and two anonymous reviewers for their constructive reviews which improved the manuscript. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF), which is a DOE Office of Science User Facility supported under contract DE-AC05- 00OR22725. This research was supported by the U.S. National Science Foundation under grant 1644826. YR was also supported by the Fundamental Research Fund for Central Universities under grant number 0206-14380080. The 2-D numerical experiments were performed on ?Tiger? at the Princeton Institute for Computational Science and Engineering, and the 42-event pilot tests were performed on the Cray XK7 supercomputer ?Titan? at the OLCF. Publisher Copyright: {\textcopyright} 2019 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.",
year = "2019",
month = jul,
day = "26",
doi = "10.1093/gji/ggz356",
language = "English (US)",
volume = "219",
pages = "1225--1236",
journal = "Geophysical Journal International",
issn = "0956-540X",
publisher = "Wiley-Blackwell",
number = "2",
}